That's a fun idea! Though, I do have to expound upon what Teanovai said. Whatever color you want, weather it's found on google or elsewhere, you can just enter the RGB numbers in their respectful areas, granted those numbers are provided.
An easy way of finding those numbers is to just screenshot the color your want, bring it into the default Paint program your computer has (hopefully,) eye drop the color and go into custom colors. There you can find the RGB numbers for the color you're currently using!
Wow that turned into a mini tutorial x'D