The YC Waveform display has an option to display Chroma. Chroma, in this case means chrominance -- the video clip's color components (hue and saturation).
The P Pro help file states: "Generally, luminance and chroma values should be about the same and distributed evenly across the 7.5 to 100 IRE range."
1) I think that is incorrect. The Chroma values are invariably spread out farther than the Luminance.
2) As far as I know, the only way to bring the Chroma values in line with the Luminance is to reduce saturation. But if you do it enough to get the Chroma value to equal Luminance, the saturation becomes zero, meaning the video clip has no color information. In addition, changing the Hue value has amost no impact on the Chroma value.
Bottom line: what is the purpose of the Chroma display in the YC Waveform?
I've never had to use it myself. I suppose it's there just in case you need to check it.