Adopted this frog off my dad. He named them Michigan but I pointed out that they're probably a girl because they've never called. We got it in the summer of 2018 as a juvenile and they lived in a biorb up until recently. They're now in a 20gallon vertical paludarium and is healthy and happy. They live next to my grey tree frog Baz who is constantly calling. But sometimes the tone can sound a bit different between calls. Today I noticed that their throat has become greener, where before it was white. Still have never caught them in the act of calling/with their throat puffed out. They're quite shy.
TDLR: Do you think they might actually be male?