Good stuff. You guys give a lot more attention to detail than I do. I just eyeball it and keep mixing paints until it looks pretty much right (wet vs. dry of course makes a difference and varnish tends to darken it). I grew up with the NA version, so as in the pic above, my Heroes are a dark red, almost burgundy, brick red color. In the years since becoming a frequenter of the Inn I've seen the brighter (almost neon) red ones rather than a blood red, and the red color used with the other red figures (Men at Arms and Ogre Warriors).
My monsters were dark green (kind of a pine green I guess in popular paint terms) but I've seen brighter/lighter green out there as well. My undead were a yellowish white. Yes, the plastic yellowed more with age but I've seen other examples and they're still not pure white... but I did get a few EU style Undead figures off ebay and they were much more white (like off white, rather than parchment or light yellow).
Oddly I've also seen that there are rare black variants of various figures. Yes, often times its just that somebody has "primed" one of their figures and so its just paint, but I have some apparently 100% real Mercs that are in black plastic (with removable weapons and everything). Could they be bootlegs? I've seen pictures of red variants of some of the Ogres (Lords, Chieftans and Champions, I mean the arms and heads here because the bodies could be dark blue or red).
The blue used for the Ogres in the EQP (or AtOH) seems different than the dark blue ("midnight blue" as many call it) used for the Wizards of Morcar figures.
I'm sure there's probably variations in the Gray as well for the Chaos figures.
I thought that Advanced Hero Quest used all gray figures (assuming you were going to paint them) but I've seen many examples online of cream colored figures, so that might have been Primer I was seeing, or perhaps it was a true variant.
Then you get the blue figures of EQP/BQP. I've seen photos of them that are pastel blue (a kind of light icy or powder blue). This is featured on the back of the boxes as well so I think that's pretty common. But some photos show them more of a brilliant blue ("Sigmar Blue" for you Warhammer fans), which might be lightning... I know Dark blue things tend to light up and look much lighter with a flash.
So I guess my point is, I understand trying to match them and make it look like "they fit" when you're doing customs, but at the same time if you don't get it quite right, don't worry, it might be a match for some other "canonical" set out there.
And it didn't dawn on me until fairly recently that the cardboard/paper standees were the official miniatures that players got in Brazil, rather than the 3d plastic sculpts. As upset as I would have been if it had been me, it's still a cool thing to preserve and also I could understand if someone was nostalgic about them.