Color dialogs now have an LCH color selector you can use instead of HSV. The LCH selector also displays out-of-gamut warning.

A new Hue-Chroma filter in the Colors menu works much like Hue-Saturation, but operates in CIE LCH color space.

The Fuzzy Select and the Bucket Fill tools can now select colors by their values in CIE L, C, and H channels.

Both the Color Picker and the Sample Points dialog now display pixel values in CIE LAB and CIE LCH at your preference.