Normal
From what I've gathered as Poecilotheria regalis grow the males tend to retain the dark stripe on their opisthoma whereas the females lose it somewhat and the stripe down their opisthoma becomes white. I've heard of exceptions to this to. I think a while back on arachnoboards I read on a thread that one dude had a Poecilotheria regalis that had a lighter stripe than most females and it matured into a large male. So it definitely isn't a great sexing method. If you can get a dorsal view though it definitely won't hurt. If you can get a ventral shot and post it here someone will likely be able to help. That's probably your best option.