Lighting fixtures are randomly reverting to a different color

I have submasters programmed to bring up a zone on the stage with all the lighting fixtures being programmed to be just white.  Randomly some of the lights will change color to either a purple or a blue, which we did use in our fall show.  I've called ETC and they had me go thru and reprogram each fixture and record the submaster(I also did a cue) and save the show.  But it still randomly change color.  Is there a way to force the fixture to automatically go to white (that would be quick fix for this)