i don't understand the reason, why write protected files should not use the same highlighting scheme as non write protected.
why is this intentional ?
from my point of view it would be much more user-friendly, if write-protected files would use exactly the same highlighting-scheme as not write protected ones.
not everyone is using svn - in many companies version-control is done by other systems, which are using file-protecting until you have checked out a specific file to work with, but normally you have to look in many other files too, which you didn't check out for editing.
i find the current highlighting handling of write-protectde files really annoing. if you can't edit a file, you know already that it's write protected, that's enough.