I think that if we did a UC Davis color test, that I would definitely also test for agouti. Glory is bred to a solid homozygous black arabian, so the agouti would affect whether she would produce a bay or black foal.
I can conclude that Misty has atleast one agouti gene that could be passed to Glory, because of her first foal. The first foal -pictured with 5yo Misty- was by a solid black (Ee) qh stallion, and when she grew up, the filly was then bred to a solid homozygous black and produced a beautiful bay colt. He didn't inherit his dam's grey gene, and stayed bay :)
The end of April can't get here quick enough to find out what is growing in her belly :)