This is a discussion on Hello there! within the Meet the Community forums, part of the The Fish Forum Community category; -->
Are all of your males in one cage?...
Plants make good hiding places. Some people use small terra cotta pots with the hole plugged up. I think colored substrate would be fine. I have colored gems in mine.
I have no idea about lighting. I have my bettas in gallon and gallon and a half containers. You do know that you can't put male bettas together, don't you?