Hello All. Sorry to use this topic for my question, but I believe is not enough to open a new one 
Related to color / tone correction, I undertand that the system work mixing input color (with its own saturation) with the color selected in the rotary selector (with also its own saturation). Also mixed result can be controlled its own saturation.
These saturation controls and color picker can obtain any color desired, isn’t it?
Also there are several modes to select. I understand the cases of RGB and TSL, but what is de difference between perceptual and normal modes?
In addition there is a “picker” that seems to select a color for the circular picker (available on “standard” and “perceptual” modes. I am struggling to undersatnd how to use it. Anyone could explain please?
Sorry for these basic questions.