Is it possible to make randomly colored objects via the compositor in Blender Internal? Is it possible to have a per object random value between 0-1 that can be used to mix two colors in Blender Internal? 

I am used to using the Object Info node in Cycles to accomplish this effect, however I have been unable to find an equivalent in Blender Internal without using third party addons.
This is relatively simple to do, pick your add on: Animation Nodes or Sverchok, and per Object color is easily done via Color props of an Object. You can use AN Object Attribute Out or SV Object Set nodes to change Object Color.



Turn on Object Color in Material, and change give different color per Object, easily visualized and will render in BI.