>> newweb4.css
I'm not sure if that's a type, but I don't ship a file called newweb4 - so if that is the actual name, then I guess whatever's in it belongs to you, not me.
If you meant netweb4.css, then that file is only there for backwards compatibility with old style apps written in Nt4. I recommend updating the app to NT5/6 standards (ie using Themes etc) before embarking on any CSS changes. Ideally your program will not use netweb4.css at all.
cheers
Bruce