Which is the best approach for a 3D model customizer?

I want to create a colour customiser for a 3d model (a tennis racket), for a webGL app. The idea is to let the player colourise different parts of the racket and create a unique custom look.

One way I can think of, is to divide the racket in submeshes and apply different materials to each one of them. Another is to apply multiple materials to the whole of the racket, each having its own alpha transparency, depending on the part it is meant to colourise. In both cases, the user will be able to change the colour of the materials via a gui.

Is there another way? Which one is better performance-wise?