Problem is that Ken's verbal description of ... let's say "Purple" ... may be different than Mary's "Violet"; which are both different than Joe's "Fuschia".

Even of you have three people actually looking at the same chip, you probably would come up with purple, violet, and fuschia. Those are marginal variations of the same basic color.

My concern is flat out color errors like dark blue/purple, dark green/brown/some shades of red, shades of gray/light blue, etc.

For those who cannot understand how someone could confuse red and green (only in some shades and saturations), consider yourself fortunate. While color blondness is more of an annoyance than a serious affliction, it can be troublesome at times.