If the spray paint aisle doesn't have the color you want, make your own. With a few materials, you can DIY a custom shade of spray paint ideal for any project.
Go on a hunt for light or dark coloured things, and name the things and the colours. Try mixing (small amounts) of black or white paint or modelling clay into bright colours to make light and dark ...
ArtistAssistApp is a web app for artists to accurately mix any color from a photo, analyze tonal values, turn a photo into an outline, draw with the grid method, paint with a limited palette, simplify ...