Magic clay bars for car washing typically come in a few standard colors, each indicating a different level of aggressiveness or intended use:

Yellow: This is often the least aggressive type, suitable for regular maintenance and light contamination removal.

Blue: A step up in aggressiveness from yellow, blue clay bars are used for moderate contamination removal, such as tree sap or stubborn dirt.

Red: Red clay bars are the most aggressive type, designed for heavy contamination removal, such as tar spots or industrial fallout.

These colors help users select the appropriate clay bar based on the level of contamination and the condition of the vehicle's paint.