Not really, Geoff. RS got some inside info from a prominent ESB model builder that going custom mixed you'll never get the colors right. Now of course, we take this information at face value. If it's right, what a relief. If it's not, back to the drawing boards.
However, the Panzer Olive Grun is dead on the ESB color. And there have been several other "in the bottle" colors that are very close to the real deal leading me to believe the majority of the suit was painted with "out of the bottle colors." The other factor to consider, besides the chance that some colors might be mixed, is the weathering process applied to the colors making them seem quite different than they do "au' natural." If you look very closely at the ESB helmet red, you'll see what appear to be untainted spots of paint, i.e. missed by weathering. I have to agree that the visor is one tough cookie. RS and I have been working our way down the paint charts looking for it.