Is there web browser with NO style as default Page style?

Is there a web browser that is so basic that it supports no page styles? Or is there a firefox extension that will apply "no style" to whatever url's you add to no style list? The reason why I ask is because I can't stand webpages that display white text on black and it is a drag to keep hitting alt+v, y, n. I wouldn't mind doing it only upon the first instance of the page but I have to keep manually changing it back to no style because though ff sometimes will remember to apply no styles as I navigate additional pages within that url, it will inevitably go back to the original annoying style.

Custom Buttons ?

Code:

https://addons.mozilla.org/en-US/firefox/addon/5066

GreaseMonkey may allow you you to write your own script to do what you want.
I bet there is a forum to help you write it, too.

Code:

https://addons.mozilla.org/en-US/firefox/addon/748

That's the 2nd time in a couple of weeks that I've been recommended Greasemonkey, never having heard of it before - I must therefore look into it even though I've solved more or less to my satisfaction this annoyance.

There's a ff add-on that places Page Style > No Style on the right click context menu. I then used the add-on Menu Edit to move Page Style to the top of the context menu so now it is faster to do than before 2 mouse clicks.

Thank you for posting your solution.
Perhaps Custom Button can do it in one click, I don't know.