How to test the achromatic power of white paint?

How to test the achromatic power of white paint?

Select a standard white paint and a standard color paste (such as black paste), add 2% carbon black paste to the standard white paint and sample paint, stir evenly, and use a parallel scraper to compare the color differences. If the color is lighter, it means there is no problem. If the color power is strong, on the contrary, it means that the ability to eliminate color is weak. <br /