Pokémon Yellow was one of my first loves. Playdates with the SNES and N64 left an impression, but the Game Boy secured in my backpack was fully mine.
Sometimes immigrant parents come in clutch: My original GBC was in perfect condition. With the help of a very cool friend I secured the parts needed to expand my universe of aftermarket mods.
My parts change out many original components to achieve this look. Most aesthetic parts are interchangeable, but if you end up with a different backlit screen, take note of which shells are actually going to fit.
Should you have experience: It'll be an easy project! There are only a few spots to connect. I followed The Retro Future's video and this imgur album for reference. Note if you change out the speaker, a desoldering pump will be clutch since the wire goes through one side to the other.
And if you don't: It's not too hard of a first project. Understandably, a full soldering set-up is an investment. Check to see if there's a local makerspace near you. They may have community tools and in-person help.
If you're up for a project that doesn't require any soldering, you can swap out the buttons and shells of your Nintendo Switch Joycons. Note that this will void any warranties.
All my parts are from eXtremeRate. And with a bit of mixing and matching, you can design yourself the colorway of your dreams. There are many videos on YouTube, so all you need to do is set aside an afternoon with patience on your side.