Unless they are, of course, actually two different colors.

Tough question, good answers.

Sometimes there are minor color variations, with the same chip design.

Sometimes there are faded, washed, or aged chips that appear to be different colors, but they aren't.

I think each chip in TCR would have to be evaluated, on an individual basis. Impossible task. So I'll assume that the autors are trying to err on the side of possibilities, rather than absolute colors.

The answer, is just as complicated. Saw the chip in half and see what color it is inside. Aside from destruction, which is in most cases, illogical, there's no way to confirm or deny with absolute certainty that one chip is just a faded twin of another, rather than a color variation.

We could surmise that lighter colors, of well know chips, are just washed out, or include all, until evidence shows they are the same?

I don't think there's a hard and fast, correct solution to the color question.

The color chart, was just an example of names for someof the colors. Where blue isn't just blue and green has various shades, all with different names.

The color sample collection sounds like fun. I have 60, and wasn't really trying to get a complete set. Now that there are seven more, maybe it's a new mission? To make things more complex, I know I have "new" chips which are not the identical color of the samples, but are intended to be that color.