About cyan-900
#104E64 is cyan-900, a tailwind v4. This page shows its rgb(16, 78, 100) / hsl(195.71, 72.41%, 22.75%) / oklch(0.3972 0.0698 227.19) 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.