Where can I download old Pokemon games?

[Tronec]

Hello, when I was a child, I missed the hype wave on Pokemons, but I remember the old Pokemon games very well. I rather play Warframe MMO games, but I really like RPG genre and I think Pokemon Red and Pokemon Yellow (colors may be wrong), it was an RPG game.

Where can I legally download them?

 

[Silktree]

The first two generations (Red through Crystal) are available via the 3DS' eShop.

Considering you posted about Serena in another thread, I assume you've played XY?

 

[Aulos]

You can only get them if you have a 3DS/2DS. The first two generations (Red/Blue/Yellow and Gold/Silver/Crystal) are available on the Virtual Console in the eShop.

EDIT: Acknowledging I got beat. lol