Unit halo colors

[db99]

I can't find anywhere that says what the little halo colors around the 3d units mean.

Usually they are white with the selected unit being red. What does it mean when the halo is yellow?

Haven't been able to figure out what that is correlating to.

[PhilThib]

The red is the selected stack, the yellow are units belonging to the same army as the selected stack...but I'll double check tomorrow in the office