How To Change PC RGB?

[TheCryptidEzra]

I'm new to the game. Not all the controls are very intuitive, so I'm struggling a little with how to figure out changing the color of the RGBs in the PC? I don't want it rainbow, just a single color. Is it possible?
I know how to change item colors, but I'm a little stuck on items that have more colors than the initial listed circles. Am I just dumb? Haha.
Thanks for the help!