Yeah so I impulsively ported the entirety of this system without knowing what it did

code/__DEFINES/color_defines.dm

@@ -157,3 +157,20 @@
 
 /// Color for dead external organs/zombies
 #define	COLORTONE_DEAD_EXT_ORGAN "#0A3200"
+
+
+/// If this is a plain atom color
+#define ATOM_COLOR_TYPE_NORMAL "normal"
+/// If this is a color filter
+#define ATOM_COLOR_TYPE_FILTER "filter"
+// Indexes for color arrays
+#define ATOM_COLOR_VALUE_INDEX 1
+#define ATOM_COLOR_TYPE_INDEX 2
+#define ATOM_PRIORITY_COLOR_FILTER "atom_priority_color"
+#define ATOM_PRIORITY_COLOR_FILTER_PRIORITY -1
+/// Multiply pixel's saturation by color's saturation. Paints accents while keeping dim areas dim.
+#define SATURATION_MULTIPLY "multiply"
+/// Always affects the original pixel's saturation and lightness.
+#define SATURATION_OVERRIDE "always"
+
+

code/__DEFINES/flags.dm

@@ -202,3 +202,19 @@ GLOBAL_LIST_INIT(bitflags, list(1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 204
 #define SCOPE_CLICK_MIDDLE 		(1<<2)
 /// Should the user hold the item in active hand to use it?
 #define SCOPE_NEED_ACTIVE_HAND 	(1<<3)
+
+// for next define
+#define KEEP_TOGETHER_ORIGINAL "keep_together_original"
+
+//setter for KEEP_TOGETHER to allow for multiple sources to set and unset it
+#define ADD_KEEP_TOGETHER(x, source)\
+	if ((x.appearance_flags & KEEP_TOGETHER) && !HAS_TRAIT(x, TRAIT_KEEP_TOGETHER)) ADD_TRAIT(x, TRAIT_KEEP_TOGETHER, KEEP_TOGETHER_ORIGINAL); \
+	ADD_TRAIT(x, TRAIT_KEEP_TOGETHER, source);\
+	x.appearance_flags |= KEEP_TOGETHER
+
+#define REMOVE_KEEP_TOGETHER(x, source)\
+	REMOVE_TRAIT(x, TRAIT_KEEP_TOGETHER, source);\
+	if(HAS_TRAIT_FROM_ONLY(x, TRAIT_KEEP_TOGETHER, KEEP_TOGETHER_ORIGINAL))\
+		REMOVE_TRAIT(x, TRAIT_KEEP_TOGETHER, KEEP_TOGETHER_ORIGINAL);\
+	else if(!HAS_TRAIT(x, TRAIT_KEEP_TOGETHER))\
+		x.appearance_flags &= ~KEEP_TOGETHER

code/__HELPERS/colour_helpers.dm

@@ -45,3 +45,112 @@
 	RGB[2] = clamp(RGB[2]+value,0,255)
 	RGB[3] = clamp(RGB[3]+value,0,255)
 	return rgb(RGB[1],RGB[2],RGB[3])
+
+//PACS related code
+
+/proc/color_transition_filter(new_color, saturation_behavior = SATURATION_MULTIPLY)
+	if (islist(new_color))
+		new_color = rgb(new_color[1], new_color[2], new_color[3])
+	new_color = rgb2num(new_color, COLORSPACE_HSL)
+	var/hue = new_color[1] / 360
+	var/saturation = new_color[2] / 100
+	var/added_saturation = 0
+	var/deducted_light = 0
+	if (saturation_behavior == SATURATION_OVERRIDE)
+		added_saturation = saturation * 0.75
+		deducted_light = saturation * 0.5
+		saturation = min(saturation, 1 - added_saturation)
+
+	var/list/new_matrix = list(
+		0, 0, 0, 0, // Ignore original hue
+		0, saturation, 0, 0, // Multiply the saturation by ours
+		0, 0, 1 - deducted_light, 0, // If we're highly saturated then remove a bit of lightness to keep some color in
+		0, 0, 0, 1, // Preserve alpha
+		hue, added_saturation, 0, 0, // And apply our preferred hue and some saturation if we're oversaturated
+	)
+	return color_matrix_filter(new_matrix, FILTER_COLOR_HSL)
+
+/// Applies a color filter to a hex/RGB list color
+/proc/apply_matrix_to_color(color, list/matrix, colorspace = COLORSPACE_HSL)
+	if (islist(color))
+		color = rgb(color[1], color[2], color[3], color[4])
+	color = rgb2num(color, colorspace)
+	// Pad alpha if we're lacking it
+	if (length(color) < 4)
+		color += 255
+
+	// Do we have a constants row?
+	var/has_constants = FALSE
+	// Do we have an alpha row/parameters?
+	var/has_alpha = FALSE
+
+	switch (length(matrix))
+		if (9)
+			has_constants = FALSE
+			has_alpha = FALSE
+		if (12)
+			has_constants = TRUE
+			has_alpha = FALSE
+		if (16)
+			has_constants = FALSE
+			has_alpha = TRUE
+		if (20)
+			has_constants = TRUE
+			has_alpha = TRUE
+		else
+			CRASH("Matrix of invalid length [length(matrix)] was passed into apply_matrix_to_color!")
+
+	var/list/new_color = list(0, 0, 0, 0)
+	var/row_length = 3
+	if (has_alpha)
+		row_length = 4
+	else
+		new_color[4] = 255
+
+	for (var/row_index in 1 to length(matrix) / row_length)
+		for (var/row_elem in 1 to row_length)
+			var/elem = matrix[(row_index - 1) * row_length + row_elem]
+			if (!has_constants || row_index != (length(matrix) / row_length))
+				new_color[row_index] += color[row_elem] * elem
+				continue
+
+			// Constant values at the end of the list (if we have such)
+			if (colorspace != COLORSPACE_HSV && colorspace != COLORSPACE_HCY && colorspace != COLORSPACE_HSL)
+				new_color[row_elem] += elem * 255
+				continue
+
+			// HSV/HSL/HCY have non-255 maximums for their values
+			var/multiplier = 255
+			switch (row_elem)
+				// Hue goes from 0 to 360
+				if (1)
+					multiplier = 360
+				// Value, luminance, chroma, etc go from 0 to 100
+				if (2 to 3)
+					multiplier = 100
+					// Alpha still goes from 0 to 255
+				if (4)
+					multiplier = 255
+			new_color[row_elem] += elem * multiplier
+
+	var/rgbcolor = rgb(new_color[1], new_color[2], new_color[3], new_color[4], space = colorspace)
+	return rgbcolor
+
+/// Recursively applies a filter to a passed in static appearance, returns the modified appearance
+/proc/filter_appearance_recursive(mutable_appearance/filter, filter_to_apply)
+	var/mutable_appearance/modify = new(filter)
+	var/list/existing_filters = modify.filters.Copy()
+	modify.filters = list(filter_to_apply) + existing_filters
+
+	// Ideally this should be recursive to check for KEEP_APART elements that need this applied to it
+	// and RESET_COLOR flags but this is much simpler, and hopefully we don't have that point of layering here
+	if(modify.appearance_flags & KEEP_TOGETHER)
+		return modify
+
+	for(var/overlay_index in 1 to length(modify.overlays))
+		modify.overlays[overlay_index] = filter_appearance_recursive(modify.overlays[overlay_index], filter_to_apply)
+
+	for(var/underlay_index in 1 to length(modify.underlays))
+		modify.underlays[underlay_index] = filter_appearance_recursive(modify.underlays[underlay_index], filter_to_apply)
+
+	return modify

code/__HELPERS/filters.dm

@@ -331,3 +331,9 @@ GLOBAL_LIST_INIT(master_filter_info, list(
 		.["offset"] = offset
 	if(!isnull(alpha))
 		.["alpha"] = alpha
+
+// PACS related
+/proc/convert_list_to_filter(list/list_filter)
+	var/list/arguments = list_filter.Copy()
+	arguments -= "priority"
+	return filter(arglist(arguments))

code/__HELPERS/trait_helpers.dm

@@ -131,6 +131,9 @@
 /// Gives a unique trait source for any given datum
 #define UNIQUE_TRAIT_SOURCE(target) "unique_source_[target.UID()]"
 
+
+
+
 /*
 Remember to update _globalvars/traits.dm if you're adding/removing/renaming traits.
 */
@@ -384,6 +387,11 @@ Remember to update _globalvars/traits.dm if you're adding/removing/renaming trai
 //traits that should be properly converted to genetic mutations one day
 #define TRAIT_LASEREYES "laser_eyes"
 
+
+/// Trait aquired from being painted a certain color
+#define ATOM_COLOR_TRAIT "atom_color"
+
+
 //status effec traits
 /// Forces the user to stay unconscious.
 #define TRAIT_KNOCKEDOUT "knockedout"
@@ -449,3 +457,6 @@ Remember to update _globalvars/traits.dm if you're adding/removing/renaming trai
 /// Proc wrapper of remove_trait. You should only use this for callback. Otherwise, use the macro.
 /proc/callback_remove_trait(datum/target, trait, source)
 	REMOVE_TRAIT(target, trait, source)
+
+///Used for managing KEEP_TOGETHER in [appearance_flags]
+#define TRAIT_KEEP_TOGETHER 	"keep-together"

code/_globalvars/traits.dm

@@ -154,6 +154,9 @@ GLOBAL_LIST_INIT(traits_by_type, list(
 
 	/atom/movable = list(
 		"TRAIT_NO_EDGE_TRANSITIONS" = TRAIT_NO_EDGE_TRANSITIONS
+	),
+	/atom = list(
+		"TRAIT_KEEP_TOGETHER" = TRAIT_KEEP_TOGETHER
 	)
 ))
 

code/datums/components/paintable.dm

@@ -26,6 +26,6 @@
 	var/colour = spraycan.colour
 	current_paint = colour
 	var/atom/A = parent
-	A.add_atom_colour(colour, FIXED_COLOUR_PRIORITY)
+	A.add_atom_colour(color_transition_filter(colour, SATURATION_MULTIPLY), ADMIN_COLOUR_PRIORITY)
 	playsound(spraycan, 'sound/effects/spray.ogg', 5, TRUE, 5)
 	to_chat(user, "<span class='notice'>You spray [spraycan] on [A], painting it.</span>")

code/game/atoms.dm

@@ -59,6 +59,9 @@
 
 	var/list/atom_colours	 //used to store the different colors on an atom
 						//its inherent color, the colored paint applied on it, special color effect etc...
+	// currently used Color filter, cached because we apply it to all of our overlays. According to the original PR author, "Byond is Horrific."
+	var/cached_color_filter
+
 
 	/// Radiation insulation types
 	var/rad_insulation = RAD_NO_INSULATION
@@ -1245,7 +1248,12 @@ GLOBAL_LIST_EMPTY(blood_splatter_icons)
 		return
 	if(colour_priority > length(atom_colours))
 		return
-	atom_colours[colour_priority] = coloration
+	var/color_type = ATOM_COLOR_TYPE_NORMAL
+	if (islist(coloration))
+		var/list/color_matrix = coloration
+		if(color_matrix["type"]=="color")
+			color_type = ATOM_COLOR_TYPE_FILTER
+	atom_colours[colour_priority] = list(coloration, color_type)
 	update_atom_colour()
 
 /*
@@ -1257,8 +1265,13 @@ GLOBAL_LIST_EMPTY(blood_splatter_icons)
 		atom_colours.len = COLOUR_PRIORITY_AMOUNT //four priority levels currently.
 	if(colour_priority > length(atom_colours))
 		return
-	if(coloration && atom_colours[colour_priority] != coloration)
-		return //if we don't have the expected color (for a specific priority) to remove, do nothing
+	if(coloration && atom_colours[colour_priority])
+		if (atom_colours[colour_priority][ATOM_COLOR_TYPE_INDEX] == ATOM_COLOR_TYPE_NORMAL)
+			if(atom_colours[colour_priority][ATOM_COLOR_VALUE_INDEX]!=coloration)
+				return // if we don't have the expected color to remove, don't do anything.
+		else
+			if(!islist(coloration) || !compare_list(coloration,atom_colours[colour_priority][ATOM_COLOR_VALUE_INDEX]["color"]))
+				return
 	atom_colours[colour_priority] = null
 	update_atom_colour()
 
@@ -1267,19 +1280,35 @@ GLOBAL_LIST_EMPTY(blood_splatter_icons)
 	colour available
 */
 /atom/proc/update_atom_colour()
+	var/old_filter = cached_color_filter
+	cached_color_filter = null
+	remove_filter(ATOM_PRIORITY_COLOR_FILTER)
+	REMOVE_KEEP_TOGETHER(src, ATOM_COLOR_TRAIT)
+
 	if(!atom_colours)
-		atom_colours = list()
-		atom_colours.len = COLOUR_PRIORITY_AMOUNT //four priority levels currently.
-	color = null
-	for(var/C in atom_colours)
-		if(islist(C))
-			var/list/L = C
-			if(length(L))
-				color = L
-				return
-		else if(C)
-			color = C
-			return
+		if (old_filter)
+			update_appearance()
+		return
+	for(var/list/checked_color in atom_colours)
+		if(checked_color[ATOM_COLOR_TYPE_INDEX] == ATOM_COLOR_TYPE_FILTER)
+			add_filter(ATOM_PRIORITY_COLOR_FILTER, ATOM_PRIORITY_COLOR_FILTER_PRIORITY, checked_color[ATOM_COLOR_VALUE_INDEX])
+			cached_color_filter = checked_color[ATOM_COLOR_VALUE_INDEX]
+			break
+		if(length(checked_color[ATOM_COLOR_VALUE_INDEX]))
+			color = checked_color[ATOM_COLOR_VALUE_INDEX]
+			break
+
+	ADD_KEEP_TOGETHER(src, ATOM_COLOR_TRAIT)
+	if(cached_color_filter != old_filter)
+		update_appearance()
+
+/// Same as update_atom_color, but simplifies overlay coloring
+/atom/proc/color_atom_overlay(mutable_appearance/overlay)
+	overlay.color = color
+	if (!cached_color_filter)
+		return overlay
+	return filter_appearance_recursive(overlay, cached_color_filter)
+
 
 /** Call this when you want to present a renaming prompt to the user.
 

code/game/objects/items/crayons.dm

@@ -38,6 +38,7 @@
 
 /obj/item/toy/crayon/suicide_act(mob/user)
 	user.visible_message("<span class='suicide'>[user] is jamming the [name] up [user.p_their()] nose and into [user.p_their()] brain. It looks like [user.p_theyre()] trying to commit suicide!</span>")
+	user.add_atom_colour(color_transition_filter(colour, SATURATION_OVERRIDE), ADMIN_COLOUR_PRIORITY)
 	return BRUTELOSS|OXYLOSS
 
 /obj/item/toy/crayon/Initialize(mapload)

code/game/objects/items/dyeing.dm

@@ -14,36 +14,42 @@
 	if(!dyeable || !dye_color)
 		return
 	var/dye_key_selector = dye_key_override ? dye_key_override : dyeing_key
-	if(!dye_key_selector)
-		return FALSE
-	if(!GLOB.dye_registry[dye_key_selector])
-		stack_trace("Item just tried to be dyed with an invalid registry key: [dye_key_selector]")
-		return FALSE
-	var/obj/item/target_type = GLOB.dye_registry[dye_key_selector][dye_color]
-	if(!target_type)
-		return FALSE
-	var/obj/item/target_obj = new target_type
-	// update icons
-	icon = initial(target_obj.icon)
-	icon_state = initial(target_obj.icon_state)
-	item_state = initial(target_obj.item_state)
-	sprite_sheets = target_obj.sprite_sheets
-	item_color = target_obj.item_color
-	desc = target_obj.desc
-	base_icon_state = target_obj.base_icon_state
+	var/has_key = TRUE // If not, we're gonna assign it using the PACS system.
+	if(dye_key_selector)
+		if(!GLOB.dye_registry[dye_key_selector])
+			stack_trace("Item just tried to be dyed with an invalid registry key: [dye_key_selector]")
+			return FALSE
+		var/obj/item/target_type = GLOB.dye_registry[dye_key_selector][dye_color]
+		var/obj/item/target_obj = new target_type
+		if(!target_type)
+			return FALSE
+		// update icons
+		if(has_key)
+			icon = initial(target_obj.icon)
+			icon_state = initial(target_obj.icon_state)
+			item_state = initial(target_obj.item_state)
+			sprite_sheets = target_obj.sprite_sheets
+			item_color = target_obj.item_color
+			desc = target_obj.desc
+			base_icon_state = target_obj.base_icon_state
 
-	// update inhand sprites
-	lefthand_file = initial(target_obj.lefthand_file)
-	righthand_file = initial(target_obj.righthand_file)
-	inhand_x_dimension = initial(target_obj.inhand_x_dimension)
-	inhand_y_dimension = initial(target_obj.inhand_y_dimension)
+			// update inhand sprites
+			lefthand_file = initial(target_obj.lefthand_file)
+			righthand_file = initial(target_obj.righthand_file)
+			inhand_x_dimension = initial(target_obj.inhand_x_dimension)
+			inhand_y_dimension = initial(target_obj.inhand_y_dimension)
+
+			// update the name/description
+			name = initial(target_obj.name)
+			qdel(target_obj)
+	else
+		has_key = FALSE
+		add_atom_colour(color_transition_filter(dye_color, SATURATION_MULTIPLY), ADMIN_COLOUR_PRIORITY)
 
-	// update the name/description
-	name = initial(target_obj.name)
 	desc += "\nThe colors look a little dodgy."
-	qdel(target_obj)
+
 	update_appearance(ALL)
-	return target_type
+	return TRUE
 
 /// Beanies use the color var for their appearance, we don't normally copy this over but we have to for beanies
 /obj/item/clothing/head/beanie/dye_item(dye_color, dye_key_override)

code/modules/clothing/under/jobs/security_jumpsuits.dm

@@ -2,6 +2,8 @@
 	icon = 'icons/obj/clothing/under/security.dmi'
 	armor = list(MELEE = 5, BULLET = 0, LASER = 0, ENERGY = 0, BOMB = 0, RAD = 0, FIRE = 20, ACID = 20)
 	strip_delay = 50
+	dyeable = TRUE
+	dyeing_key = FALSE
 	sprite_sheets = list(
 		"Human" = 'icons/mob/clothing/under/security.dmi',
 		"Vox" = 'icons/mob/clothing/species/vox/under/security.dmi',

code/modules/mob/living/carbon/human/human_update_icons.dm

@@ -614,7 +614,7 @@ GLOBAL_LIST_EMPTY(damage_icon_parts)
 					else
 						standing.overlays += image("icon" = 'icons/mob/accessories.dmi', "icon_state" = "[tie_color]")
 			standing.alpha = w_uniform.alpha
-			standing.color = w_uniform.color
+			standing = w_uniform.color_atom_overlay(standing)
 			overlays_standing[UNIFORM_LAYER] = standing
 
 	else if(!dna.species.nojumpsuit)
@@ -816,7 +816,7 @@ GLOBAL_LIST_EMPTY(damage_icon_parts)
 				bloodsies.color = shoes.blood_color
 				standing.overlays += bloodsies
 			standing.alpha = shoes.alpha
-			standing.color = shoes.color
+			standing = shoes.color_atom_overlay(standing)
 			overlays_standing[SHOES_LAYER] = standing
 	else
 		if(feet_blood_DNA) // Checks for feet to make sure we don't have mysterious floating blood.
@@ -887,7 +887,7 @@ GLOBAL_LIST_EMPTY(damage_icon_parts)
 			bloodsies.color = head.blood_color
 			standing.overlays += bloodsies
 		standing.alpha = head.alpha
-		standing.color = head.color
+		standing = head.color_atom_overlay(standing)
 		overlays_standing[HEAD_LAYER] = standing
 	apply_overlay(HEAD_LAYER)
 
@@ -979,7 +979,7 @@ GLOBAL_LIST_EMPTY(damage_icon_parts)
 			standing.overlays += special_overlays
 
 		standing.alpha = wear_suit.alpha
-		standing.color = wear_suit.color
+		standing = wear_suit.color_atom_overlay(standing)
 		overlays_standing[SUIT_LAYER] = standing
 
 	apply_overlay(SUIT_LAYER)
@@ -1056,7 +1056,7 @@ GLOBAL_LIST_EMPTY(damage_icon_parts)
 				standing.overlays += bloodsies
 
 			standing.alpha = wear_mask.alpha
-			standing.color = wear_mask.color
+			standing = wear_mask.color_atom_overlay(standing)
 			overlays_standing[FACEMASK_LAYER] = standing
 	apply_overlay(FACEMASK_LAYER)
 
@@ -1107,7 +1107,8 @@ GLOBAL_LIST_EMPTY(damage_icon_parts)
 
 		//create the image
 		standing.alpha = back.alpha
-		standing.color = back.color
+		//standing.color = back.color
+		standing = back.color_atom_overlay(standing)
 		overlays_standing[BACK_LAYER] = standing
 	apply_overlay(BACK_LAYER)
 

code/modules/power/lights.dm

@@ -613,7 +613,7 @@
 		hsl[3] = max(hsl[3], 0.4)
 		var/list/rgb = hsl2rgb(arglist(hsl))
 		var/new_color = "#[num2hex(rgb[1], 2)][num2hex(rgb[2], 2)][num2hex(rgb[3], 2)]"
-		color = new_color
+		color = add_atom_colour(color_transition_filter(new_color, SATURATION_MULTIPLY), ADMIN_COLOUR_PRIORITY)
 		to_chat(user, "<span class='notice'>You change [src]'s light bulb color.</span>")
 		brightness_color = new_color
 		update(TRUE, TRUE, FALSE)