diff --git a/code/__HELPERS/sanitize_values.dm b/code/__HELPERS/sanitize_values.dm
index cbe1817233..21ae7df940 100644
--- a/code/__HELPERS/sanitize_values.dm
+++ b/code/__HELPERS/sanitize_values.dm
@@ -51,40 +51,106 @@
 				return default
 	return default
 
-/proc/sanitize_hexcolor(color, desired_format=3, include_crunch=0, default)
+#define RGB_FORMAT_INVALID 0
+#define RGB_FORMAT_SHORT 1
+#define RGB_FORMAT_LONG 2
+
+/**
+  * Sanitizes a hexadecimal color.
+  *
+  * @params
+  * * color - input color, 3 or 6 characters without the #.
+  * * desired_format - 3 or 6 characters without the potential #. can only put in 3 or 6 here.
+  * * include_crunch - do we put a # at the start
+  * * default - default color. must be 3 or 6 characters with or without #.
+  * * default_replacement - what we replace broken letters with.
+  */
+/proc/sanitize_hexcolor(color, desired_format = 3, include_crunch = 0, default = "ffffff", default_replacement = "f")
+	if(!istext(default) || (length(default) < 3))
+		CRASH("Default should be a text string of RGB format, with or without the crunch, 3 or 6 characters. Default was instead [default]")
+	if(!istext(default_replacement) || length(default_replacement) != 1))
+		CRASH("Invalid default_replacement: [default_replacement]")
+	switch(text2ascii(default_replacement))
+		if(48 to 57)
+		if(97 to 102)
+		if(65 to 70)
+		else		// yeah yeah i know 3 empty if's..
+			CRASH("Invalid default_replacement: [default_replacement]")
 	var/crunch = include_crunch ? "#" : ""
 	if(!istext(color))
-		color = ""
+		color = default
 
-	var/start = 1 + (text2ascii(color, 1) == 35)
 	var/len = length(color)
-	var/char = ""
-	// RRGGBB -> RGB but awful
-	var/convert_to_shorthand = desired_format == 3 && length_char(color) > 3
+	// get rid of crunch
+	if(len && color[1] == "#")
+		if(len >= 2)
+			color = copytext(color, 2)
 
-	. = ""
-	var/i = start
-	while(i <= len)
+	switch(desired_format)
+		if(3)
+			desired_format = RGB_FORMAT_SHORT
+		if(6)
+			desired_format = RGB_FORMAT_LONG
+		else
+			CRASH("Invalid desired_format: [desired_format]. Must be 3 or 6.")
+	var/current_format = RGB_FORMAT_INVALID
+	switch(length(color))
+		if(3)
+			current_format = RGB_FORMAT_SHORT
+		if(6)
+			current_format = RGB_FORMAT_LONG
+		else
+			current_format = RGB_FORMAT_INVALID
+
+	if(current_format == RGB_FORMAT_INVALID)		// nah
+		color = default		// process default
+		if(color[1] == "#")		// we checked default was at least 3 chars long earlier
+			color = copytext(color, 2)
+		len = length(color)
+		switch(len)
+			if(3)
+				current_format = RGB_FORMAT_SHORT
+			if(6)
+				current_format = RGB_FORMAT_LONG
+			else
+				CRASH("Default was not 3 or 6 RGB hexadecimal characters: [default]")
+
+	var/sanitized = ""
+	// first, sanitize hex
+	for(var/i in 1 to len)
 		char = color[i]
 		switch(text2ascii(char))
-			if(48 to 57)		//numbers 0 to 9
-				. += char
-			if(97 to 102)		//letters a to f
-				. += char
-			if(65 to 70)		//letters A to F
-				. += lowertext(char)
+			if(48 to 57)			// 0 to 9
+				sanitized += char
+			if(97 to 102)			// a to f
+				sanitized += char
+			if(65 to 70)			// A to F (capitalized!)
+				sanitized += lowertext(char)
 			else
-				break
-		i += length(char)
-		if(convert_to_shorthand && i <= len) //skip next one
-			i += length(color[i])
+				sanitized += lowertext(default_replacement)
+	// do we need to convert?
+	if(desired_format == current_format)
+		return crunch + sanitized		// no
+	// yes
+	if((desired_format == RGB_FORMAT_SHORT) && (current_format == RGB_FORMAT_LONG))			// downconvert
+		var/temp = ""
+		// we could do some math but we're lazy and in practice floor()ing this.
+		for(var/i in 1 to 6 step 2)
+			temp += sanitized[i]
+		sanitized = temp
+	else if((desired_format == RGB_FORMAT_LONG) && (current_format == RGB_FORMAT_SHORT))		// upconvert
+		var/temp = ""
+		for(var/i in 1 to 3)
+			temp += sanitized[i]
+			temp += sanitized[i]
+		sanitized = temp
+	else
+		CRAHS("Invalid desired_format and current_format pair: [desired_format], [current_format]. Could not determine which way to convert.")
+	return crunch + sanitized
 
-	if(length_char(.) != desired_format)
-		if(default)
-			return default
-		return crunch + repeat_string(desired_format, "0")
-
-	return crunch + .
+#undef RGB_FORMAT_INVALID
+#undef RGB_FORMAT_SHORT
+#undef RGB_FORMAT_LONG
 
 /proc/sanitize_ooccolor(color)
 	if(length(color) != length_char(color))