New Banners: This idea has been brought up a few times in the input box, and many approve of this, it brings it the creativity in people. There was once an Art contest held on the forum for members of FH to join, it was rather successful, with many entries made. I'm sure if there was a banner contest, it would result to a success of some sort. But as Sura said, with the preset contests, FH party events and other important things, I don't think this type of event is ready to be held yet. Though, it's good to see another person encouraging it~
Colours for member groups: I will leave this one, it has already been explained the way it is needed. Though I'm sure people appreciate your attempt on making the forum more bright and colourful. Maybe the one day banner contest will take it's toll and give that more appealing effect to the boards.
More contests/Board for this(not sure if this exist): As good as that sounds, Sura has explained it more than enough, but just to add to it, there is an events board where you could host your own contest/event. It's what it is there for at least c: Adding more and more boards and sub boards would make things more full and complicated for new members who might arrive at FH. Also got to think about making use of other boards too~
As you can see, I have left the last ones out as some of it is mostly to do with staff stuff, though Sura has explained it really well and carefully.