This should all work, but I'm getting unrelated compile errors.

code/modules/organs/organ_external_vr.dm

@@ -1,3 +1,6 @@
+/obj/item/organ/external
+	var/transparent = 0 //For better slime limbs
+
 //Sideways override for nanoform limbs (ugh)
 /obj/item/organ/external/robotize(var/company, var/skip_prosthetics = FALSE, var/keep_organs = FALSE)
 	var/original_robotic = robotic

code/modules/organs/organ_icon.dm

@@ -206,7 +206,7 @@ var/global/list/limb_icon_cache = list()
 
 /obj/item/organ/external/proc/apply_colouration(var/icon/applying)
 
-	if(nonsolid)
+	if(transparent) //VOREStation edit
 		applying.MapColors("#4D4D4D","#969696","#1C1C1C", "#000000")
 		if(species && species.get_bodytype(owner) != SPECIES_HUMAN)
 			applying.SetIntensity(1) // Unathi, Taj and Skrell have -very- dark base icons. VOREStation edit fixes this and brings the number back to 1
@@ -235,7 +235,7 @@ var/global/list/limb_icon_cache = list()
 		//VOREStation Edit End
 
 	// Translucency.
-	if(nonsolid) applying += rgb(,,,180) // SO INTUITIVE TY BYOND
+	if(transparent) applying += rgb(,,,180) // SO INTUITIVE TY BYOND //VOREStation Edit
 
 	return applying
 

code/modules/organs/subtypes/slime_vr.dm

@@ -0,0 +1,32 @@
+/obj/item/organ/external/chest/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/groin/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/arm/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/arm/right/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/leg/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/leg/right/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/foot/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/foot/right/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/hand/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/hand/right/unbreakable/slime
+	transparent = 1
+
+/obj/item/organ/external/head/unbreakable/slime
+	transparent = 1