This is my first build out of an old bike. After some refinements, the black tank & fenders were looking dull. So I just painted them to go a little with the green bike. I like candy paints.
I've been custom painting since 14 yo. Candy paint like this get a base like silver (here). The color is translucent to see the base through it. I just fade out one color. Change the color in the spraygun and fade the new color in and next to the other. You can do this with other paints also.
Then a clearcoat makes it permanent