Best approach to changing decal color at runtime


Ive tried hard to find a previous post covering this, but alas, I could not.

I was just wondering if there is a method to change colour of decal at runtime (or at least set a custom colour). My specific case is a very simple png with only pure black (0x000000) or transparent areas. However playing with diffuse/ colour property, nothing changes. What is the best approach?

I played around with setting a geometry color attribute (ive done it for other models), but it didnt work.

Is png the best file, does svg provide better results in threejs?

Any help would be appreciated.