As the title says, if I have an object with:
- Object Color with green, alpha 0.5, for example.
- Object Color activated in Material - Options.
- Shadeless activated in Material - Shading.
In viewport, the object is tending to green and semi-transparent. I think also in GE.
Rendering in BI, the object is not affected by "Object Color" color and/or alpha.
The workarround would be the object not to be shadeless and Emmit at 1, as @Juan Pablo Bouza (jpbouza) said in http://blenderartists.org/forum/showthread.php?175963-2-50-animate-everything-object-visibility&p=1798282&viewfull=1#post1798282.