Babies enjoy the bright colours. It's for them, not you. Mine is very neutral, but very bright. Yes it was an eye sore in the living room when we had it out, but she loved it and that's all that matters. I'm sure she wouldn't have enjoyed playing on a grey playmat with nothing to look at.
Re: Neutral playmats.
I realize that babies like bright colours. I'm just having a hard time finding one that isn't overwhelmingly busy.