Paint a texture dynamically?

Hi guys! im doing my first proyect in unity, and i need some guidance about this. Dont really know if it can be done or not, so here am i :3.

Here is the thing:

Lets say i have 3 adjacent boxes that can be green blue or yellow each, and insteed i want to have 1 big GameObject with the same dimension and appearance (to minimize resources).

there is a way to texture it dynamically?? without having to create all the different combinations it may have manually (only the "basic" ones)?

Such as: `"use blue material/texture/etc from x0-x50, yellow x50 - x100"` and so on?

Code will be appreciated, but what i really want is knowing if it can be done and were i have to deepen my knowledge, and if it's worth trying or the resources been consumed by the 3 boxes will be the same as the big one :). Thanks!