I’ve almost always heard my customers refer to the grease that they are using by its colour. They would say, “I’m using the blue grease.” However, greases are not defined by their colour. Colour is often added to grease to allow it to be easily identifiable within the field. For instance, if a grease is coloured blue, it is easy to identify if it’s leaking or not (one way not to confuse the leak with an oil leak).
Some greases are coloured to ensure that the applicant uses it in the correct application. For example, if a blue grease is a multipurpose grease then this ideally shouldn’t be used in the very high temperature area. Most of the times, red greases are used for high temperature applications. Thus making it easy to identify if the correct grease is used in the right application. However, one should note the colours of the greases being used in their facility and their applications before comparing them to that of another facility (which may be using a different grease manufacturer.)
Don’t define greases by their colours, define them by their applications!