I use very gentle (30 day wash out) coloring on my hair since in the end it will be donated. It's to keep the grey out of the top area. For some reason the grey hairs don't grow long, so the actual ponytail I donate never has any grey in it. So that's good.
In any case, I don't think that I vary my hair color based on seasons. I have 3 or 4 I go between, all "dark brown", and I sort of randomly choose whatever strikes me at the moment. I should track what I choose - maybe I do choose lighter / darker and don't even realize it!
Lisa Shea, Low Carb / Video Games EditorLow Carb Forum