You could do this by placing in an animation. Add the two images you want for your object, uncheck loop in the animation box. So it should be the first image while object is still then when it wakes up it should change to the second image. I haven't tried this but i think it will work... maybe, i hope, ill try it.
Thanks @playsgames6666 Im trying to no avail but will try other things too It would be real cool if the animation editor in there worked like the ones in the UI then I could just turn the alpha down on one frame then up on the other. Edit: There is a neat little effect when used with a spawner, the wakeup doesn't kick in until your close enough (mine is distance based) then once spawned the frame of the animation id delayed to show the other image. Hacked and different results achieved but workable thanks @playsgames6666
