Acid #3 is a bright pop of neon yellow--think highlighter yellow--that leans almost a little green-ish. It had a matte finish with semi-sheer color payoff. It pops a lot more if patted over a white base, but the chalky, powdery texture keeps it from being easily used on its own or over a regular primer. This shade stains somewhat, and it lasts about seven hours before there's noticeable fading and light creasing. MAC Bright Yellow (P, $15.00) is warmer, more muted. Inglot #370 (P, $6.00) is warmer. See comparison swatches.