SynLube™ Lube−4−Life® INITIAL FILL is opaque black and usually it will not change in color.
Under some conditions it may slightly change its color, depending on the engine. Over the past several years, diesel engines have been designed to minimize the generation of smoke from the engine -- with a considerable amount of this soot being handled by detergents and dispersants in the engine oil. High-quality diesel engine oil is formulated to handle high soot levels.
SynLube™ Lube−4−Life® may become blacker relatively quickly as it does its job, depending on how much soot your engine produces. In gasoline engines some fuel additives that are used in gasoline may also cause slight color change to a brownish tint, that is normal and not cause for concern.
The quality of SynLube™ Lube−4−Life® can not be judged by its color, only complete laboratory analysis can determine the condition of any lubricant.
To fully understand how and why SynLube™ Lube−4−Life® is the "Best Lubricant" please read this more detailed web page: