Specific colour is so difficult, if you
paint under electric light or natural light
take your reference from a book, a screen all depends on how they are set up
and everyone sees colour slightly different
and human sees more shades of green than any other colour, it being a survival thing about knowing what is safe to eat!!!!!
I certainly have painted stuff at night and 'in the day light' have thought to myself....how did i think THAT looked good. The thing about colour is its relationship to what is around it. Sometimes photographing an object in a different coloured back ground can make it look better or worse!!!!
So sometimes following a particular path, i.e. a single brand of colours means their inter relationship is better IF the original person who made them had a 'good' eye for colour, and if you own EYES agrees!!!!!
I think if YOU do a good paint job, and the colour is in the right area, you should feel chuffed, and if someone states that they think the colour is off, it is a personal opinion, and opinion can be a moot point, and some people will say good and others disagree. The whole issues of a moot point is that it is not definitive but objective, and unfortunately colour is objective, AND in some cases we don't have enough historical evidence to be 100% .
I still have not found the really good site that compares the different brands of paint....should i stumble over it later I will add it and PM you, or better still pop it on your thread....if i remember by then.......