#53A4CC

CSS

:root {
  --mystic-blue: #53a4cc;
  --mystic-blue-rgb: 83 164 204;
  --mystic-blue-oklch: oklch(0.684 0.099 232.2);
}

.element {
  color: var(--mystic-blue);
  background-color: hsl(200 54% 56%);
  border-color: oklch(0.684 0.099 232.2);
}

Tailwind CSS v4

@theme {
  --color-mystic-blue: #53a4cc;
  --color-mystic-blue-50: #dbfbff;
  --color-mystic-blue-100: #c9eeff;
  --color-mystic-blue-200: #abdcf9;
  --color-mystic-blue-300: #84c0e3;
  --color-mystic-blue-400: #5da9cf;
  --color-mystic-blue-500: #3191bc;
  --color-mystic-blue-600: #2c7b9f;
  --color-mystic-blue-700: #23627f;
  --color-mystic-blue-800: #15485e;
  --color-mystic-blue-900: #0e3242;
  --color-mystic-blue-950: #011e2a;
}

SCSS

$mystic-blue: #53a4cc;
$mystic-blue-rgb: 83, 164, 204;
$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);
}