Im just gonna add that adding a paintpack that holds Every single color its something Hard/Impossible to code, for the same reason each color painter takes 1 Item ID Each.
And in case nobody read, Painters have a Auto Refill mode, just equip your painter change the mode and be sure to have some Dye of the corresponding color in your inventory, exactly the same as a paint pack but without needing to equip it on your torso.