Imagine I want to visit `webmaster.stackexchange.com` (or an other website) everyday but I want to change the blue color of header (change it to red for instance).

Is it possible to force personal css styles when I visit a website? If so, how can I do it? Maybe a web browser tip or a plugin? (I use Chrome)

I would like an automatic solution, change css with web browser console (F12 on Chrome) for each page I visit is not interesting.