Draw an illustration in gray.

Color with a gradient map.

Go to Layer → New Tonal Correction Layer → Gradient Map.

Select your favorite gradation.

Adjust the opacity of the gradient map layer slightly. This time I set it to 70%.

I want to make the color a little darker, so I use a level correction layer.

Go to Layer → New Color Correction Layer → Level Correction.

Adjust the number. Please move the part of the arrow.

carry out!

Various gradation map usage examples.