#0D7690

CSS

:root {
  --celestial: #0d7690;
  --celestial-rgb: 13 118 144;
  --celestial-oklch: oklch(0.525 0.093 221);
}

.element {
  color: var(--celestial);
  background-color: hsl(192 83% 31%);
  border-color: oklch(0.525 0.093 221);
}

Tailwind CSS v4

@theme {
  --color-celestial: #0d7690;
  --color-celestial-50: #d9fcff;
  --color-celestial-100: #c7f0ff;
  --color-celestial-200: #a9def2;
  --color-celestial-300: #81c2da;
  --color-celestial-400: #59abc5;
  --color-celestial-500: #2894b1;
  --color-celestial-600: #257d96;
  --color-celestial-700: #1e6478;
  --color-celestial-800: #124a58;
  --color-celestial-900: #0b333e;
  --color-celestial-950: #001f27;
}

SCSS

$celestial: #0d7690;
$celestial-rgb: 13, 118, 144;
$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);
}