I have no idea what Pokemon is nor do I have any desire to find out. The fact that there are males my age into it leaves me speechless.
In 1999 Nintendo was trying to wean gamers off the B&W Game Boy and onto the backwards compatible Game Boy Color. Pokemon Yellow: Special Pikachu Edition was a re-release of Pokemon Yellow with some support for the Game Boy Color built it. Yeah, every classic Game Boy game worked in the Game Boy Color but there were some tricks to make games look better in the newer system. This was a way for Nintendo to support both systems while giving people the hint that they should upgrade, similar to their Twilight Princess strategy.
I've received some feedback noting that several Game Boy Color games were compatible with the original Game Boy. This was the last game made specifically for the original Game Boy and it's perfectly debatable whether the Game Boy Color games "count". For the sake of completeness, the two Dragon Warrior Monsters 2 titles, released in September 2001, earn the distinction of being the final Game Boy compatible games.