#1E7590

CSS

:root {
  --celestial: #1e7590;
  --celestial-rgb: 30 117 144;
  --celestial-oklch: oklch(0.525 0.089 223.7);
}

.element {
  color: var(--celestial);
  background-color: hsl(194 66% 34%);
  border-color: oklch(0.525 0.089 223.7);
}

Tailwind CSS v4

@theme {
  --color-celestial: #1e7590;
  --color-celestial-50: #dbfbff;
  --color-celestial-100: #caefff;
  --color-celestial-200: #acddf1;
  --color-celestial-300: #85c1da;
  --color-celestial-400: #5faac5;
  --color-celestial-500: #3593b1;
  --color-celestial-600: #2f7c96;
  --color-celestial-700: #256378;
  --color-celestial-800: #184958;
  --color-celestial-900: #0f333e;
  --color-celestial-950: #021e27;
}

SCSS

$celestial: #1e7590;
$celestial-rgb: 30, 117, 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);
}