Starry Sky Blue

CSS

:root {
  --starry-sky-blue: #4f5e7e;
  --starry-sky-blue-rgb: 79 94 126;
  --starry-sky-blue-oklch: oklch(0.483 0.055 265);
}

.element {
  color: var(--starry-sky-blue);
  background-color: hsl(221 23% 40%);
  border-color: oklch(0.483 0.055 265);
}

Tailwind CSS v4

@theme {
  --color-starry-sky-blue: #4f5e7e;
  --color-starry-sky-blue-50: #eef5ff;
  --color-starry-sky-blue-100: #e0e8fb;
  --color-starry-sky-blue-200: #cad4ed;
  --color-starry-sky-blue-300: #abb7d4;
  --color-starry-sky-blue-400: #8f9ec0;
  --color-starry-sky-blue-500: #7486ab;
  --color-starry-sky-blue-600: #637191;
  --color-starry-sky-blue-700: #4f5b74;
  --color-starry-sky-blue-800: #384356;
  --color-starry-sky-blue-900: #262e3c;
  --color-starry-sky-blue-950: #151b26;
}

SCSS

$starry-sky-blue: #4f5e7e;
$starry-sky-blue-rgb: 79, 94, 126;
$starry-sky-blue-light: mix(#fff, $starry-sky-blue, 20%);
$starry-sky-blue-dark: mix(#000, $starry-sky-blue, 20%);

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