I would like a much lighter colour, not black, for my timeline and interface. I am using Win 7 Premium with a 64 bit resolution. Software is Magix Edit Pro MX Plus
I'm pretty certain you can't! I think the basic colour is a "dark" one in order to provide a high level of contrast between it and your video footage, though I may be completely wrong on that!
Agree with Jeff there is no auto way of changing skins. When the dark dark background was first introduced there were IIRC some threads on the old forum about adapting the changes to earlier versions of MEP, but I can't find them now.
The images used are in the same directory as your main .exe file, perhaps in folders names 'Skins' or BItmaps'. Presumably you could alter these in any photo editing program -- having made backups of course -- but I agree with Jeff that the darker version makes the preview window really shine.
Also going to agree with Jeff and Carl. Though Carl has the right idea in terms of getting into the skins and bitmaps and changing them with a photo editor. Actually, the Magix Extreme photo designer would probably do the trick. You could go for a custom look if you are just going to change the main skin, but if you wanted to change the look of the buttons individually, that might be a bit tricky. I think there are a few buttons which work off a pallet, rather than their own individual bitmap image for each button. If that were the case, it could still be changed, but would involve someone who is really ambitious. It would be very time consuming, in other words. If I were you, I would stick with the darker interface. I think Jeff is correct about why the interface is dark, though.