the first listing is a GBC that got its original shell replaced by a third party shell (not Nintendo original). You can buy these shells for a couple of bucks on aliexpress.
There are give or take 60 Pokémon themed special versions spanning across nearly every generation of Nintendo console. A lot of these were sold exclusively at Pokémon Centers, but the more elusive ones saw distribution through special promotions in the Daisuki Club , store-specific limited time offers, tournament rewards and one was even obtainable through smpratte’s favorite way: a raffle. A good overview of these consoles can he found here.
Needless to say with anything Pokémon, a nice sealed or mint copy of any of these consoles will fetch a premium.
Popular ones include:
GameBoy Advance SP - Pikachu Edition ($600-$700)
Pokémon GameBoy Light ($650+)
GameBoy Micro - Pokémon Edition ($600-$700)
GameBoy Advance SP - Rayquaza Edition ($300-$500)
Pokémon Third Anniversary GameBoy Color ($300-$400)
The console you posted is the first variant of this console:
Pokémon GameBoy Color
US Release Date: October 2000
European Release Date: April 6th 2001
Australian Release Date: October 2000
Price: $99.99
Model: GameBoy Color
Pack-in Game: None
Description:
This special GameBoy Color features Pikachu & Pichu to the side of the screen and has come in three variants. One is a special Gold & Silver version, to tie in with the release of Pokémon Gold & Silver, exclusive to Toys’ R’ Us, while another is silver and a final one which was released in yellow.