The color classifications of several Pokemon are wrong. For example, Mega Charizard X is classified as "red", however it's most recent classification is "black"
This is due to the fact that many Pokemon got reclassified in generation 7, and continued to be reclassified in future entires as alternate forms gained their own entries in games
Bulbapedia has a list of these changes, and an up-to-date list of all the current color classifications https://bulbapedia.bulbagarden.net/wiki/List_of_Pok%C3%A9mon_by_color