GM Original Equipment™ Dex-Cool™ Engine Cooling System Tracer Dye by ACDelco®. Volume: 1 oz. Color: Fluorescent Lime Green. ACDelco offers a full range of oils, fluids, and vehicle care products to protect, enhance, and maintain your automobile. From adhesives, sealants, and cleaners to lubricants, waxes, and paints, ACDelco has all you need to keep your vehicle looking and performing great.