There's colors that cover good and poor in both light and dark colors and also differences in brands/paint lines. Some of the really cheap paint out there covers so poorly that it doesn't make any economic sense to use it and with the ones that mix in a 2:1 ratio you lose 25% sprayable right off the bat-there's a significant amount of solvent already in the paint if it only requires a 50% reduction. Example- PPG has Omni and Omni Plus-both budget line paints and some of the colors in these lines may take 6 coats with regular Omni, 4 coats with Omni Plus and if you go to one of their premium lines like Global or Nexa that same color might reach full coverage in two coats. There are some colors that seem to cover poorly in every line-these are usually made more with dyes and pearls rather than traditional pigments-they are more transparent. The only way to know what you're dealing with is to shoot a test panel-it takes very little time and very little material. If you're worried about buying a significant quanitity of color for a complete only to find it covers poorly have the supplier mix up a half pint and do a coverage test panel. 99 Acura Integra Dark green fine metalic-if it's the color I'm thinking it is I bet it will cover well in most paint lines. On full interior/exterior/underside completes I order 6 quarts of base minimum and usually end up with one quart left over for future repairs if needed-that's with quality paint offering 3 coat coverage. Before I started testing coverage I remember being burned on one paint line, $400/gallon, 2:1 ratio, basic gold metalic. 2.5 gallons later the job was done, no left overs for repairs, 15 quarts of sprayable went on that car and I also looked for ways to cheat it by using similar colored undercoats and recomended sealer color with no luck-7 coats minimum for full coverage and a consistant paint match. It pays to sample and test color coverage on large jobs.