Hi Alfred,
I have a light colored soft top and I can tell you they are a bugger to keep clean, not so much the day to day dust and dirt but if any rubber rubs or they rub whilst down and the cover closed, it is near impossible to remove the marks from the rubber or from the lid rubbing on it. If I had my time again I would go with a darker soft top just so that it always looks ok.
Regards
Garry