http://www.beauty-and-nutrition.com/...y_fashion.html
Have your Mom check out this site and many others for a fashion update.
This link is fun because it debunks other fashion myths as well.
Personally I don't follow rules set by people I don't know, very well. What I follow is what makes sense for me. Light weight white pants and sandals in January in MN would be insane....but white wool slacks and white boots, totally cool! In Florida just the opposite would be true.
Common sense and free thinking prevail.