So basically, How would i make the RGB values in this (https://doy2mn9upadnk.cloudfront.net/uploads/default/original/4X/8/0/3/803e200b00a5e47e2a6bd36c4ffd53f8e68baa0d.rbxm) apply to any part i want. If you need me to be more clearer or the link does not work then please contact me.
I hope you understand this color picker uses color3, and parts use BrickColor, BrickColor has set colors and doesnt run off an RGB scale however you would have to convert Color3 to a BrickColor value, and inside the update() function in the localscript of the gui you just set the parts BrickColor