adds custom light option for robots (#16534)

code/modules/mob/living/silicon/robot/life.dm

@@ -375,7 +375,7 @@
 
 /mob/living/silicon/robot/handle_light()
 	if(lights_on)
-		set_light(integrated_light_power, 1, "#FFFFFF")
+		set_light(integrated_light_power, 1, robot_light_col)
 		return TRUE
 	else
 		. = ..()

code/modules/mob/living/silicon/robot/robot.dm

@@ -15,6 +15,7 @@
 	blocks_emissive = EMISSIVE_BLOCK_UNIQUE
 
 	var/lights_on = 0 // Is our integrated light on?
+	var/robot_light_col = "#FFFFFF"
 	var/used_power_this_tick = 0
 	var/sight_mode = 0
 	var/custom_name = ""

code/modules/mob/living/silicon/robot/robot_ui.dm

@@ -62,6 +62,7 @@
 	data["max_charge"] = R.cell?.maxcharge
 	data["health"] = R.health
 	data["max_health"] = R.getMaxHealth()
+	data["light_color"] = R.robot_light_col
 
 	data["weapon_lock"] = R.weapon_lock
 
@@ -111,6 +112,11 @@
 	var/mob/living/silicon/robot/R = host
 
 	switch(action)
+		if("set_light_col")
+			var/new_color = params["value"]
+			if(findtext(new_color, GLOB.is_color))
+				R.robot_light_col = new_color
+			. = TRUE
 		if("select_module")
 			R.pick_module()
 			. = TRUE