Bright and fun, there are some new bits on the sight that would look great in a boys or girls bedroom.
As all the walls in our house are white, we add colour with bright prints on the walls. Etsy has the most brilliant selection of designs that you won't find on the high street. One of my favourite sellers is ModernPop, based in LA they sell to the UK.
Alternatively a cheap and easy way to brighten up a nursery is to try framing comic books or images taken from old children's books.
I like using the white frames from Ikea to show of simple, graphic prints.