How to make materials easier to see on adjacent meshes

I have tried to make a simple person out of Unity cubes, but when applying the materials, I saw that they look like they are joined, as the material is the same colour.

[30858-material+glitch.jpg|30858]

What can I do to stop this? Are there any shaders that can stop this?

This is all due to how the scene is lit. With just ambient light, and solid colour materials this will always happen. If you introduce a directional or other light source you should start seeing some more definition (assuming the cubes are not equally deep and flush on the front face with each other).

Also make sure in scene view to turn the lighting on (the little symbol next to 2D at the top) this lets you see a little closer to how it looks in game view and is useful for setting up lighting without having to run the game all the time.

Further definition can come from all sorts of things, more detailed geometry, textures in the material, edge highlighting shaders etc.