The real question is if the color is indicative of the purity. In some cases a ppb trace of a compound can color a sample, in other cases a grossly impure sample can be colorless.
So before making a compound for medicinal chemistry, there should be a standard QC protocol, often including NMR, LC-MS, CHN, mp/bp, or other methods, with predefined levels of purity wished to be attained before assaying the compound. But be aware that none of those methods are perfect, as NMR will not detect many non-hydrogen containing solvents or salts, MS cannot see many organics which do not ionize, LC-UV does not see many solvents and non-aromatics, and every analytical method is only so good. But often 95% or better is good enough for simple assays, and then if further tests are to be done, a more detailed prep and analysis are in order.