You could, as there’s no rule against it, but I haven’t really seen people do it. Now, part of that is that most handlers are middle-aged to older women who probably don’t wear shorts much of the time if at all, anyway.
Most people try to match the color of the dog, which is pretty much impossible with a yellow (nice thing about black dogs). As the judge said to me last weekend “black dog, black floor, black pants and a navy blue background (was hanging on the ring gates) ... I don’t know WHAT I’m seeing!”. In other words, matching the dog can hide a bad front, LOL.
I have a feeling when I first start showing the yellow girls, I’ll still be showing Chloe, so will be wearing black - their fronts will be VERY noticeable!
So the answer is, you can, but you will most likely be the only one.
Edited to add - I’ve never shown to this judge but I’ve heard she can be a VERY tough scorer. Your choice of clothes shouldn’t affect that though, LOL.