>>18529951Red, Green, Blue, Yellow - Red
Gold, Silver, Crystal - Gold
Ruby, Sapphire, Emerald - Ruby
Fire Red/Leaf Green - Fire Red
Diamond, Pearl, Platinum - Diamond
Heart Gold/Soul Silver - Heart Gold
Black/White - Black
Black 2/White 2 - Black 2
X/Y - X
How would you know? Heroe's name (in case of R/G/B/Y/G/S/C, manga, and beta/pre-release phases) comes from the first version. Rival's from either second or third/upgraded, depending if you can call your rival or not - so in case of R/G/B Heroines is Blue, but in case of R/S/E Heroine is Sapphire, who later became May.
The only games to don't have their colour counterpart-characters are Yellow (the only fourth/upgraded version) and Emerald, which was fixed in the manga.