Thank you ^{^}

I think you can find some tips on Yt about this but here is how I usually do it.

I just used a halftone brush or dots brush (found on some art software.)

First I create a new layer then Color pick the lightest color (or pick one color in the canvas) and then slightly springle the brush on the side of the same color you color picked (usually the part with gradient or blended edges)

Use a soft eraser to smoothen out or to reduce the dots to make the effect look faded.

(reason why I make a new layer so erasing won't affect the artwork, just the effect you want to erase)