if you don't specify a color when registering a trademark, you can use other colors even if the registered trademark is black and white.

on the other hand, if a color is specified, but it is used in black and white or other colors, it is regarded as a substantial change to the trademark and belongs to improper use of the trademark.

if different colors are used, there are two possibilities. First, it registered a black and white trademark and used different colors. The second is to register two trademarks with different colors.

This is the case in China, but other countries don't know it.