Up to you. Someone in Discord asked about purple and white and my response is the same: whatever you wish, this jam is meant to be fun #1 and constraints are #2
Some things have changed, in the Discord we voted on having a secondary theme and it won out that we will. Anyone can post a secondary theme idea and it will get randomly chosen 2 days before the jam starts.
I'm not the host, but I would think that anti-aliasing would make it no longer "1 bit". Of course if that's not something you can turn off in your environment, then whatevs... as PureNukage keeps saying, it's all about having fun!
