Apply 3 coats of spray paint

I use matt paint (wait for the previous coat to dry)

In my case

1 coat of matt white

here I use blue and green in the same proportion as the original photo ⅓ , 2/3

1 coat of matt black

We are going to engrave in reverse image

Black will be the lightest

white will be the darkest

The coloured part must be grey (don't lighten the image too much, otherwise you won't get the colour of the paint between the white and the black).