What are the regulations regarding trademark color changes?

Generally speaking, registered trademarks are mostly black and white drafts. When using them, the trademark registrant can add color to the registered trademark according to actual needs. However, the trademark pattern after adding color should be different from the registered trademark pattern (black and white draft) only in black and white and color, without any substantial difference. If the color added to the original registered trademark can form a special pattern that can exist independently or the color divides the original registered trademark pattern into two completely different parts, the overall visual effect of the original registered trademark pattern is lost, which is considered a change in the trademark pattern.