Quoting dcologne:

Quote:
Hallo ,

as an newby there is one question.
How can I editing an existing theme. For example I want to
change the colour of some figures or the size of some figures.
What have I to do for that ?

Thank you and my regards
dcologne

Try right clicking on different areas.  Many of them let you tinker with colors and such that way.  Other than that, you would have to load a particular theme into the editor part of the program and save it under a different name.  Then open up the saved one and tinker away.