BTW this is not to say that I wont have a go at helping you, however a few things first - is this the actual size of the piece? and is it a flat layer or is it several layers? If it is in layers or you have a larger version feel free to email it to me.
To get the background one colour, make a new layer, choose the paintbucket tool and then click on the top of the two colour viewers in the tools pallette and then select the colour you want, finally click on the canvas with the colour you want (if you want to pick a colour from an existing image, press 'I' on the keyboard and then sample (copy) that colour by left clicking mouse once)
I am happy to help you complete this, but I fall short of doing it for you as you learn nothing from that, and I sense that you want to learn.