Yellow

#fff200

This is yellow at full volume: an L* near 95 and a b* value close to 96 make it one of the brightest, most saturated swatches in the book, with a very slight green lean that keeps it from turning golden. Next to Black it produces the hard, cautionary contrast of road signs and hazard tape, and with Carmine or Blue it falls into primary-color directness. It is unusable as text on white at 1.2:1, yet black lettering on it reaches 18:1, which is why it works so well behind headlines. Use it for safety graphics, children's packaging, or a single painted door.