#1A7590

CSS

:root {
  --celestial: #1a7590;
  --celestial-rgb: 26 117 144;
  --celestial-oklch: oklch(0.524 0.09 223.2);
}

.element {
  color: var(--celestial);
  background-color: hsl(194 69% 33%);
  border-color: oklch(0.524 0.09 223.2);
}

Tailwind CSS v4

@theme {
  --color-celestial: #1a7590;
  --color-celestial-50: #dbfbff;
  --color-celestial-100: #c9efff;
  --color-celestial-200: #abddf2;
  --color-celestial-300: #84c2da;
  --color-celestial-400: #5eaac5;
  --color-celestial-500: #3193b2;
  --color-celestial-600: #2c7c96;
  --color-celestial-700: #236378;
  --color-celestial-800: #164958;
  --color-celestial-900: #0e333e;
  --color-celestial-950: #021e27;
}

SCSS

$celestial: #1a7590;
$celestial-rgb: 26, 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);
}