Blue Planet

CSS

:root {
  --blue-planet: #545e6a;
  --blue-planet-rgb: 84 94 106;
  --blue-planet-oklch: oklch(0.478 0.023 253);
}

.element {
  color: var(--blue-planet);
  background-color: hsl(213 12% 37%);
  border-color: oklch(0.478 0.023 253);
}

Tailwind CSS v4

@theme {
  --color-blue-planet: #545e6a;
  --color-blue-planet-50: #f1f6fc;
  --color-blue-planet-100: #e3e8f0;
  --color-blue-planet-200: #ced5de;
  --color-blue-planet-300: #b0b8c3;
  --color-blue-planet-400: #95a0ac;
  --color-blue-planet-500: #7c8796;
  --color-blue-planet-600: #69737e;
  --color-blue-planet-700: #545c65;
  --color-blue-planet-800: #3d434a;
  --color-blue-planet-900: #2a2e34;
  --color-blue-planet-950: #171b1f;
}

SCSS

$blue-planet: #545e6a;
$blue-planet-rgb: 84, 94, 106;
$blue-planet-light: mix(#fff, $blue-planet, 20%);
$blue-planet-dark: mix(#000, $blue-planet, 20%);

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