I don't like having too much blue around the stadium, especially the outside. Only because some seriously qualified designers and architects designed the stadium to look the way it is. I trust their judgement. They've got it right. OK grey not be the most vibrant of colours, but they've chosen it as their colour scheme, so we should stick with it. Plastering it with blue paint and signs would make it look tacky.
Same with 'MCFC' in the stands. The all blue seats looks nice, neat and sleak. And as had been mentioned, the noise levels won't rise within the stadium because someone's sat on a white seat that forms the 'M' of MCFC.
A few more banners around the stadium would make it a bit more personal, we've only got 3. A big banner saying something decent, or even just a giant crest would look good.
Singing sections...this idea's flawed the from the very start. The atmosphere will always be better where the away fans are. Everyone's talking about moving the away fans, to put the south east corner and south stand together to create one big singing section. It won't happen. If you moved the away fans to say, the north stand, then all the noise makers will just move to the north stand, either side of the away fans and the south stand will be dead.
You need to have small pockets of fans, maybe supporters club branches dotted around the stadium. Hopefully these lot will get on a coach together, got to a pub together, then get in the ground together and start some singing and atmosphere.
Plus, there's only so much encouraging you can do. If people don't want to make noise, they won't.