About yellow-100
#FEF9C2 is yellow-100, a tailwind v4. This page shows its rgb(254, 249, 194) / hsl(55, 96.77%, 87.84%) / oklch(0.9727 0.0706 103.29) values, WCAG contrast against black and white, an OKLCH tint-and-shade ramp, and complementary, analogous, and triadic harmonies — all computed in perceptually-uniform OKLCH.