I agree Greg, I think in the end the best we can do is to try to come to an agreement of which type fits the category...but if Carlos knows of any source for clarification I think that might be helpful. If not, we will continue on our own.
I did notice that Shreiner's has Sharpshooter listed as an amoena, yet the AIS describes the standards as being a pale lavender-blue. Perhaps they think the falls are more of a red-violet than a blue-violet? Our database has it as a neglecta.
When I find ones that are clearly mis-categorized I change the database, but if it's open to interpretation then I leave it alone.