Hi Jason,
If you're mixing colours, you're better to start with paints that use a single known pigment - cobalt blue, azo yellow, vermilion, that kind of thing. The reason is based in substractive colour theory. It's a long story and I don't fully understand it myself, but you'll get a cleaner colour mixing 2 pure pigments than mixing 2 colours that are already a mix of 2 or 3 different pigments, because each time you mix pigments you absorb more light and reduce the amount that reflects out. This means the more pigments you put in, the duller, browner or muddier the result looks. A lot of old paintings that you might see in galleries have very dull muddy greens, because the green and yellow pigments didn't last, and paintings where the sky is almost black are often a result of the use of cheaper blues. There was a topic on here, or maybe in MRJ a while back about the constituents of NER green and how the blue component faded faster than the yellow (I think), that might be worth looking up. There was something about copper in the pigment.
For a quick fix with modern pigments, Artist's colours are the best source of single pigment colours. They generally have a number, eg, PY27 and PY 31 would be yellows. PB45 a blue, PBG70 a blue-green. In other words, P is for pigment, followed by a colour letter or 2, followed by a number. Fewer pigments are better for mixing. Most greens are an unholy concoction of everything you can think of, so not great for making new colours.
Acrylic is good for cover but if you want a really fine finish, you might need to use oils, built up in several coats.
As a starting point, I'd look at azo yellow, cobalt blue and a good deal of white - and maybe experiment with some phthalocyanine green as well. Make up a colour chart, mixing different proportions from pure yellow to pure blue, repeat for pure yellow to pure green and pure blue to pure green. That will give you an idea of the range of colours available. Then take the ones that are in the right sort of colour range and add white to them in increasing amounts until you decide you've gone too far.
You'll get a much better understanding of this if you look up proper explanations and don't rely on the above. And an even better one by sitting down with a few sheets of A2 paper and filling them with colour permutations.
Have fun, and try not to paint the dining room table.
Alan