Every game that was marketed as "Gameboy Color" but was on a regular shaped cartridge could be played on the classic Gameboy, that was intentional. There's plenty of those games. Link's Awakening is another, I think there's even a few cases where it's the other way around.
The only difference was that "Color" games never had a standard grey cartridge but were always colored (I think usually they were black). The "Color" games that had a cartridge where the top banner stuck out (thick instead of hollow, like how 3DS cartridges have that hook on it preventing them from being used in DS's) were the ones that weren't compatible with older Gameboy models. These were usually only late Gameboy games. The back of game boxes of games released after the Gameboy Color came out also mentioned which models a game was compatible with.
Those Pokemon games were "Gameboy exclusives", but not exclusive to only the Color model. The correct answer is "No", because the back of the box said so.
