Rgb info to hue/ saturation in nuke

how can I take rgb info sampled from the nuke viewer and translate that into hue and saturation info that can be used in the HueCorrect node ?

Here’s a good way reference with conversion codes for different color spaces. It’s in Java but the python translation should be obvious.

neat, thats ok, but how to apply the changes of conversion to hueCorrect node in nuke… ?