Shale Grey

CSS

:root {
  --shale-grey: #899da3;
  --shale-grey-rgb: 137 157 163;
  --shale-grey-oklch: oklch(0.682 0.024 217.7);
}

.element {
  color: var(--shale-grey);
  background-color: hsl(194 12% 59%);
  border-color: oklch(0.682 0.024 217.7);
}

Tailwind CSS v4

@theme {
  --color-shale-grey: #899da3;
  --color-shale-grey-50: #eef7fa;
  --color-shale-grey-100: #dfeaed;
  --color-shale-grey-200: #c9d7db;
  --color-shale-grey-300: #aabbc0;
  --color-shale-grey-400: #8fa2a8;
  --color-shale-grey-500: #758a91;
  --color-shale-grey-600: #63757b;
  --color-shale-grey-700: #4f5e62;
  --color-shale-grey-800: #394548;
  --color-shale-grey-900: #272f32;
  --color-shale-grey-950: #151c1e;
}

SCSS

$shale-grey: #899da3;
$shale-grey-rgb: 137, 157, 163;
$shale-grey-light: mix(#fff, $shale-grey, 20%);
$shale-grey-dark: mix(#000, $shale-grey, 20%);

.element {
  color: $shale-grey;
  box-shadow: 0 0 0 2px rgba($shale-grey, 0.35);
}