#6D748A

CSS

:root {
  --abandoned-spaceship: #6d748a;
  --abandoned-spaceship-rgb: 109 116 138;
  --abandoned-spaceship-oklch: oklch(0.561 0.035 271.3);
}

.element {
  color: var(--abandoned-spaceship);
  background-color: hsl(226 12% 48%);
  border-color: oklch(0.561 0.035 271.3);
}

Tailwind CSS v4

@theme {
  --color-abandoned-spaceship: #6d748a;
  --color-abandoned-spaceship-50: #f2f5ff;
  --color-abandoned-spaceship-100: #e4e7f4;
  --color-abandoned-spaceship-200: #cfd4e4;
  --color-abandoned-spaceship-300: #b1b7ca;
  --color-abandoned-spaceship-400: #979eb4;
  --color-abandoned-spaceship-500: #7d859e;
  --color-abandoned-spaceship-600: #6a7186;
  --color-abandoned-spaceship-700: #555a6b;
  --color-abandoned-spaceship-800: #3d424f;
  --color-abandoned-spaceship-900: #2a2e37;
  --color-abandoned-spaceship-950: #181a22;
}

SCSS

$abandoned-spaceship: #6d748a;
$abandoned-spaceship-rgb: 109, 116, 138;
$abandoned-spaceship-light: mix(#fff, $abandoned-spaceship, 20%);
$abandoned-spaceship-dark: mix(#000, $abandoned-spaceship, 20%);

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