Fixes #5780

code/modules/mob/living/simple_mob/subtypes/slime/slime.dm

@@ -129,17 +129,18 @@
 /mob/living/simple_mob/slime/proc/unify()
 	unity = TRUE
 
-// Interface override, because slimes are supposed to attack other slimes of different color regardless of faction
+// Interface override, because slimes are supposed to attack other slimes of different color regardless of faction.
 // (unless Unified, of course).
 /mob/living/simple_mob/slime/IIsAlly(mob/living/L)
 	. = ..()
-	if(.) // Need to do an additional check if its another slime.
-		if(istype(L, /mob/living/simple_mob/slime))
-			var/mob/living/simple_mob/slime/S = L
-			if(S.slime_color != src.slime_color)
-				if(S.unity || src.unity)
-					return TRUE
-				return FALSE
+	if(istype(L, /mob/living/simple_mob/slime)) // Slimes should care about their color subfaction compared to another's.
+		var/mob/living/simple_mob/slime/S = L
+		if(S.unity || src.unity)
+			return TRUE
+		if(S.slime_color == src.slime_color)
+			return TRUE
+		else
+			return FALSE
 	// The other stuff was already checked in parent proc, and the . variable will implicitly return the correct value.
 
 // Slimes regenerate passively.

html/changelogs/Mechoid-Slimefix.yml

@@ -0,0 +1,36 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes: 
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscadd (general adding of nice things)
+#   rscdel (general deleting of nice things)
+#   imageadd
+#   imagedel
+#   maptweak
+#   spellcheck (typo fixes)
+#   experiment
+#################################
+
+# Your name.  
+author: Mechoid
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, all entries are changed into a single [] after a master changelog generation. Just remove the brackets when you add new entries.
+# Please surround your changes in  double quotes ("), as certain characters otherwise screws up compiling. The quotes will not show up in the changelog.
+changes: 
+  - bugfix: "Slimes now respect slime colors as their faction when dealing with other slimes."