ktRainbowColors maya mel script
assigns unique colors to each polygon objects in your scene.(generates only a shader)
by the way you can detect objects clear way on viewport and render.
its a good method while predesigning a scene,animation or detecting object seperations or combined objects and collisions. it is a good method. because you can see any object clearly. because all becomes a unique objects. and brain can detect some bad collisions or bad forms or bad designs with a clear way.
1- put mel script to Scripts Directory
2- optional:put png into icons directory. required icon if you create a shelf button.
execute this command :
Each execution, generates random colors for each polygons in your scene.so if you dont think they are contrast colors enough. just re-execute the code above.