#0D7691

CSS

:root {
  --celestial: #0d7691;
  --celestial-rgb: 13 118 145;
  --celestial-oklch: oklch(0.525 0.094 221.8);
}

.element {
  color: var(--celestial);
  background-color: hsl(192 84% 31%);
  border-color: oklch(0.525 0.094 221.8);
}

Tailwind CSS v4

@theme {
  --color-celestial: #0d7691;
  --color-celestial-50: #d9fcff;
  --color-celestial-100: #c7efff;
  --color-celestial-200: #a9def2;
  --color-celestial-300: #81c2db;
  --color-celestial-400: #59abc6;
  --color-celestial-500: #2894b2;
  --color-celestial-600: #257d97;
  --color-celestial-700: #1e6479;
  --color-celestial-800: #124a59;
  --color-celestial-900: #0b333e;
  --color-celestial-950: #001f27;
}

SCSS

$celestial: #0d7691;
$celestial-rgb: 13, 118, 145;
$celestial-light: mix(#fff, $celestial, 20%);
$celestial-dark: mix(#000, $celestial, 20%);

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