Which method is less intensive?

I'm making a 2D game that is fairly basic. The player has to navigate a maze like level, collect green orbs, and dodge grey orbs. The maze itself is just made up of cubes made in Unity set to various sizes.

So my question is: Is it better to set a my material on each one of those cubes, or just have the cubes be white and project the material onto them with a projector? The game runs fine either way, I was just wondering if one was a “best practice” over another.

I would say... Just change the texture thats already on the cubes...