Acid-fast and Colorfast

Acid-fast adjective - Not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis).

Colorfast and acid-fast are semantically related. In some cases you can use "Colorfast" instead an adjective phrase "Acid-fast".

Colorfast adjective - Having color that is resistant to fading or running.

Acid-fast and colorfast are semantically related. You can use "Acid-fast" instead an adjective "Colorfast".