Color adjustment in this palette, as well as D-Range Optimizer, is rather supplementary.
There are few cases where [Hue] adjustment is necessary; basically leave it to the default setting "0."
[Saturation] changes density of colors. Move the [Saturation] slider toward plus for vivid color, toward minus for pale color. If set to -100, the image becomes black and white.
For example, if you take pictures on a foggy day, distant landscape is often reproduced with low contrast and pale color. If you slightly enhance the [Contrast] and [Saturation] in this case, the picture looks clear.
Too much adjustment makes the subject unnatural and sometimes causes the loss of color gradation. Move the slider slightly while viewing the images.