you can either fuck around on this site, and then edit the xml file (instructions or on the lower left of the page)
http://arkku.com/elite/hud_editor/


or you can get EDprofiler, and it has some preconfigured settings
http://www.drkaii.com/tools/edprofiler/


it changes a bit of things with the hud, for example, i run a blue theme, so enemies on my radar are a dark blue, not red.

a bit of googling will get you some options to try.


im using:
<MatrixRed>0.21, 0.29, 0.93</MatrixRed>
<MatrixGreen>0, 1, 0</MatrixGreen>
<MatrixBlue>1, 1, 1</MatrixBlue>