Maybe someone else has already mentioned this but in addition to available color swatches on the HSL panel an eye-dropper tool to pick the precise color you want to adjust would be nice. On one of my older cameras the blue represented in a sky that is too close to the sun comes out looking all electric and needs to be corrected. A color picker here would zero in on the problem straight away.
Hi Andrew - - You forgot to vote for your request/suggestion.
Regards, John M
Thanks John.
Hi @MonUncle and thanks for your feedback and suggestion.
This feature will ease the work with the colorwheel and is indeed already in our Backlog.
I’ll close the topics to free the Votes 
Best regards,
The DxO Team