There is one CSS snippet that I have been copy-pasting for 5 years: * { background-color: rgba(255,0,0,.2); } * * { background-color: rgba(0,255,0,.2); } * * * { background-color: rgba(0,0,255,.2); } * * * * { background-color: rgba(255,0,255,.2); } * * * * * { background-color: rgba(0,255,255,.2); } * * * * * * { background-color: rgba(255,255,0,.2); } * * * * * * * { background-color: rgba(255,0