About gray-50
#F9FAFB is gray-50, a tailwind v4. This page shows its rgb(249, 250, 251) / hsl(210, 20%, 98.04%) / oklch(0.9846 0.0017 247.84) 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.