My daughter has been trying to help me but she thought it would be faster if I asked here.  I bought a new phone today (Samsung S5511T).  The theme on it is a black background with white writing, the lady in the shop told me I wouldn't be able to change this but I noticed that I'm able to choose from 3 themes on the phone and is it possible to load a new theme on the phone that's a little easier to read i.e. black writing on a white background.

Thank you for any help you are able to give.