Imagine you can change the LAB L* without affecting Saturation/Hue
Imagine you can change Saturation without affecting Hue/L*
Imagine a new representation of RGB color model
True Achrome (a*=b*=0 ; H=S=0 ; B=L*)
Hue UP (+10), no change for Sat/L*
Saturation UP (+10), no change for Hue/L*
L* (Lstar) UP (+10), no change for Sat/Hue
Can you do this, with only one adjustment layer ?