I recently purchased 3 B. Oreintalis
when i picked them out i chose 2 smaller ones and one large one, thinking the larger of the three would be female and the other two male. (their names are Red, Green and Black hehe)
after only one night i realized i was very wrong, turns out the smallest of the three is a female and the other two male. this is simply because of age/poor feeding im sure.
i did alot of research trying to figure out how to sex them

Males:
-Call
-have rougher pimplier skin
-have thicker forearms/front legs
-do a special "unmounting call" when another male accidently goes into amplexus with it
-have nuptial pads

Females
-dont call
-have smoother skin
-tend to be slightly larger ( but not always)

I also read something about the coloring of them but I dont think it is reliable information.

anyways this is based on my research and own observations i just thought id share, i might be wrong on some of this stuff too, its not set in stone or anything

i will try to get pictures/videos soon