#6C719F

CSS

:root {
  --twinkle-night: #6c719f;
  --twinkle-night-rgb: 108 113 159;
  --twinkle-night-oklch: oklch(0.563 0.071 279);
}

.element {
  color: var(--twinkle-night);
  background-color: hsl(234 21% 52%);
  border-color: oklch(0.563 0.071 279);
}

Tailwind CSS v4

@theme {
  --color-twinkle-night: #6c719f;
  --color-twinkle-night-50: #f1f3ff;
  --color-twinkle-night-100: #e3e6ff;
  --color-twinkle-night-200: #ced1f3;
  --color-twinkle-night-300: #b0b4dc;
  --color-twinkle-night-400: #959bc9;
  --color-twinkle-night-500: #7c81b5;
  --color-twinkle-night-600: #696e99;
  --color-twinkle-night-700: #54587b;
  --color-twinkle-night-800: #3c405b;
  --color-twinkle-night-900: #292c40;
  --color-twinkle-night-950: #171929;
}

SCSS

$twinkle-night: #6c719f;
$twinkle-night-rgb: 108, 113, 159;
$twinkle-night-light: mix(#fff, $twinkle-night, 20%);
$twinkle-night-dark: mix(#000, $twinkle-night, 20%);

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