Coal Seam
Long sessionsSecurity and monitoring consoles that run warm instead of the usual blue glow.
Click a swatch to copy its hex.
Do not use this for
Daylight data entry — the warm cast lowers text crispness under glare.
What was measured
- Closest neighbours
- ΔE00 11
- how alike two adjacent swatches look
- Darkest to lightest
- 5.52:1
- WCAG contrast across the set
- Lightness covered
- 47 pts
- of OKLCH lightness, 0–100
- Under colour blindness
- ΔE00 6.9
- worst under protanopia
These two are one colour to a reader with protanopia. Fine while the set is read as an order; never use them to mean two different things without a label or an icon as well.
A suggested mapping · derived, then measured
Five colours are not an interface, so this is an offer rather than a token set. It does not clear WCAG AA on secondary text and the accent — stated here rather than left for you to discover.
/* Coal Seam — Security and monitoring consoles that run warm instead of the usual blue glow. */
:root {
--palette-1: #1d030e;Tailwind
// tailwind.config — Coal Seam
export default {
theme: {For your coding agent · printed from the colours
Use the Coal Seam palette: #1D030E, #47141F, #6E312F, #865A4D, #9C8375. It is for this: Security and monitoring consoles that run warm instead of the usual blue glow.
How this palette was built · no hex was chosen by hand
The catalog states a recipe — ramp from hue 24 — and the five colours are derived from it in OKLCH, where a step of lightness is a step your eye agrees with rather than one the hex numbers agree with. That is why the numbers above are properties of this palette rather than claims about it.