Header size and menu bar color

I have the home page http://tekstiltrolden.dk and I´m really happy for my theme, but I want to change some colors on it. I would like to change the color of my primary and secondary menu bar, but I can´t figure out how I do it ? I would also like to change the size on my header so it could be higher, where can I change the  ? I hope you can help me Sorry my english it is not the best, but I hope you understand me ;) Best regards Anne-Pia Hansen