Switching Solid Color Materials for a Texture Atlas

I started making 3D Games using Unity and I noticed some people have severe slowdown issues when playing my games. From some research, I learned about the best practices when making games to help with the memory usage.

What I've tried so far is to disable gameobjects when they're not shown onscreen and lowering the Clipping Planes Far value. They worked well, but I also read that using too many materials is bad for the memory usage and data processing. Currently I'm using about 30 materials with solid colors - lots of models are using more than one material.

I know two possible routes I could take are Vertex Coloring and Texture Atlases (using one material). I don't want to use Vertex Coloring for now since I have no experience, so I'm trying Texture Atlas. The thing is - it's a lot of work to make one, so I'm starting to question if it really is a good idea to make one using solid colors.

Has someone here used Texture Atlas like this before? Should I worry about creating one? Thanks for the attention!