RGB to hex

Shows any colour as hex, RGB, HSL and OKLCH together, so converting is a matter of reading the line you need rather than running a conversion.

Hex and RGB are the same numbers written differently — `#3366cc` is red 51, green 102, blue 204, each pair of hex digits being one channel in base 16. That is why the conversion is exact and lossless in both directions. HSL is a genuine transformation and is where the interesting behaviour lives: it is easy to reason about, and its lightness is not perceptual, so two colours at the same HSL lightness can look very different in weight. OKLCH fixes that, which is why it is worth knowing about even though hex remains the format everything accepts.