I understand your plight with browser integrations. However, since IE has made newer browsers, browser codes from 6 are not compatible with v5.5 and they aren't compatible with v5, etc.... There is no more real browser integration codes. There was a belief before that XML coding might help and that it can give the right hues of colors. I just saw a conference with regards to this and it was mentioned they cannot really tell the difference from candy red to cherry red.
Just like photoshop or a printer, there are certain colors used (mainly 6) to try and mix the right tones/hues to portray them as closely as possible. This ofcourse with the new XML coding does not always read in accordance with all browsers.
Hopefully future codes will be more cross platform based but, as everyone knows, MS & Modzilla type browser companies are like children fighting for the only chocolate chip cookie. Not willing to share/split it.