If you have facebook, there are a ton of pictures under the Disney Princess Half Marathon fan page that show the shirts. They were blue. Your husband is allowed. There were 400 men! Most were dragged by their SO's and some added some humor to it! Men can race, they just aren't eligible for the awards - other than one pair award. I can't remember what it was called. Was the couple award? They do get the medal that everyone who finishes gets. The shirt wasn't too girly. I think it is great that he wants to do it.
BTW, you don't have to wear the shirt. I don't wear anything when racing that I haven't before. That way, I don't run into issues with comfort, chafing, etc. My shirt has never been worn. I probably will when I start training the
Disneyland Half. But, I am just paranoid as I have had plenty of bad experiences with new gear. I test out everything. I think evidently a lot of people didn't do that beforehand, because within the first mile, a ton of stuff was being dumped. It was Christmas for some of the runners in the corrals after us!