OK, if you say so (there is still the option to switch between CSS in the VIEW option on the most browsers anyway). And where did you see a security flaw in the script?
Well it isn't a big concern but it's just an annoying part. I run a caching plugin so it'll cache whatever page you're viewing. Let's see you used blue css on naruto ep200 and the next user who tries to watch naruto ep200 will see a blue css instead of what ever colour they picked.