Its in line with the definition of Dominant Wavelength (17-23-062 | CIE), but I confess it is a bit of a mouthful and isn’t as intuitive for colors along the line of purples.
It could also potentially be described as a “purity” transform (17-23-066 | CIE), e.g. “at higher luminances we reduce the (colorimetric excitation) purity”…
But this really is bikeshedding…