There isn’t a universal standard for what color grease means what. Some brands may have their own color schemes (eg. red for high-temperature grease, or using colors to indicate thickener types). Other brands simply use color as a marketing thing—for example, Lucas Oil makes their signature “red and tacky” grease, which is red as you might imagine.

From a bit of research, some other purposes of grease color include:

• differentiating different greases in an industrial setting where generic, unlabeled grease guns are used.
• serving as a visual indication of contaminated or overheated grease by allowing workers to observe changes in color.

Note that some black greases have that color due to additives such as molybdenum disulfide or graphite. Don’t mix those up with grease that is simply dyed black. Similarly, white grease may contain Teflon as an additive.

There isn’t a universal standard for what color grease means what. Some brands may have their own color schemes (eg. red for high-temperature grease, or using colors to indicate thickener types). Other brands simply use color as a marketing thing—for example, Lucas Oil makes their signature “red and tacky” grease, which is red as you might imagine.

From a bit of research, some other purposes of grease color include:

• differentiating different greases in an industrial setting where generic, unlabeled grease guns are used.
• serving as a visual indication of contaminated or overheated grease by allowing people to observe changes in color.

Note that some black greases have that color due to additives such as molybdenum disulfide or graphite. Don’t mix those up with grease that is simply dyed black. Similarly, white grease may contain Teflon as an additive.