Removes most instances of item_color

Notable exception is for clothing/under, those will have to be removed once item_state override is implemented.

code/game/objects/items/weapons/implants/implant.dm

@@ -9,7 +9,7 @@
 	var/implanted = null
 	var/mob/imp_in = null
 	var/obj/item/organ/external/part = null
-	item_color = "b"
+	var/implant_color = "b"
 	var/allow_reagents = 0
 	var/malfunction = 0