Yes, this is how I interpreted it. Arguably before the 20th century we had few commonplace references for most of the hues we've now named at all. Plus, most of

Yes, this is how I interpreted it. Arguably before the 20th century we had few commonplace references for most of the hues we've now named at all. Plus, most of the references we do have are often localized regionally and linguistically to people who recognize the term. The constant colors—things like "blood" and "dark" and "bright-white"—are actually pretty rare. Even the sun, the sky, the ocean, earth etc are capable of producing far too many hues to reliably use as a reference point, and often different hues in different place. Which is not so say that it's not very poetic when it works!