#0C283F

CSS

:root {
  --midnight-ocean: #0c283f;
  --midnight-ocean-rgb: 12 40 63;
  --midnight-ocean-oklch: oklch(0.268 0.055 246.6);
}

.element {
  color: var(--midnight-ocean);
  background-color: hsl(207 68% 15%);
  border-color: oklch(0.268 0.055 246.6);
}

Tailwind CSS v4

@theme {
  --color-midnight-ocean: #0c283f;
  --color-midnight-ocean-50: #eaf7ff;
  --color-midnight-ocean-100: #daeafa;
  --color-midnight-ocean-200: #c3d7eb;
  --color-midnight-ocean-300: #a2bad3;
  --color-midnight-ocean-400: #85a2bd;
  --color-midnight-ocean-500: #698aa9;
  --color-midnight-ocean-600: #59758f;
  --color-midnight-ocean-700: #475d72;
  --color-midnight-ocean-800: #324554;
  --color-midnight-ocean-900: #222f3b;
  --color-midnight-ocean-950: #111c25;
}

SCSS

$midnight-ocean: #0c283f;
$midnight-ocean-rgb: 12, 40, 63;
$midnight-ocean-light: mix(#fff, $midnight-ocean, 20%);
$midnight-ocean-dark: mix(#000, $midnight-ocean, 20%);

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