#4AA4CE

CSS

:root {
  --mystic-blue: #4aa4ce;
  --mystic-blue-rgb: 74 164 206;
  --mystic-blue-oklch: oklch(0.681 0.105 231.4);
}

.element {
  color: var(--mystic-blue);
  background-color: hsl(199 57% 55%);
  border-color: oklch(0.681 0.105 231.4);
}

Tailwind CSS v4

@theme {
  --color-mystic-blue: #4aa4ce;
  --color-mystic-blue-50: #d9fbff;
  --color-mystic-blue-100: #c6efff;
  --color-mystic-blue-200: #a8ddfb;
  --color-mystic-blue-300: #7fc1e5;
  --color-mystic-blue-400: #56a9d2;
  --color-mystic-blue-500: #2392bf;
  --color-mystic-blue-600: #217ba1;
  --color-mystic-blue-700: #1b6382;
  --color-mystic-blue-800: #0e495f;
  --color-mystic-blue-900: #093243;
  --color-mystic-blue-950: #001e2b;
}

SCSS

$mystic-blue: #4aa4ce;
$mystic-blue-rgb: 74, 164, 206;
$mystic-blue-light: mix(#fff, $mystic-blue, 20%);
$mystic-blue-dark: mix(#000, $mystic-blue, 20%);

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