With time and wear, the quality, consistency, and color of your motor oil will change. Truthfully, you should not only rely on color to dictate the efficiency of oil. Depending on the oil, the color will alter for various reasons, including heat, additives, and contaminants. What Color is Oil Supposed To Be? Engine oil color is not as significant as people make it out to be. Oil can naturally get dark and still be effective in doing its job. However, as a general rule new, clean oil should be amber or honey color. What Causes Motor Oil To Turn Black? Thick, dark, and sometimes black motor oil usually indicates that your oil has been exposed to dirt or outside contaminants that lead to a soot accumulation. Soot is a byproduct of inadequate combustion, and in moderate amounts, should not cause engine damage. The problem with soot is that sometimes it can agglomerate into something bigger. This is where the thick black texture may be more pronounced. If you want to be on the safe side ... read more