I thought you wanted to get rid of the blue?
Here is what to do step by step:
1) Click Start on your computer
2) Click 'Control panel' (depending on what set up you have, you may actually have to hover the mosue cursor over the title 'settings' first of all then click control panel
3) Double click the 'display' icon (usually a computer icon)
4) Click the tab which says 'Apperance'.
5) Then fiddle around with what you find, experiment.
6) When you want to try something out, click the 'apply' button then 'ok' button. Go back to your desktop and see how it looks. If you want to change it again, just repeat the above steps.
Hope this helps.