The reply feature is coming first thing tomorrow morning according to one of our programmers. In the meantime, you'll have to do it the goofy way: signaling that you're replying to someone with re: username

Colored text is also upcoming soon-ish. The big advantage of this thing being made basically from scratch is that it's very modular and we can add so much, but it does mean that some default proboards/forum features are not implemented yet.