#6F71AE

CSS

:root {
  --twinkle-night: #6f71ae;
  --twinkle-night-rgb: 111 113 174;
  --twinkle-night-oklch: oklch(0.573 0.093 281.6);
}

.element {
  color: var(--twinkle-night);
  background-color: hsl(238 28% 56%);
  border-color: oklch(0.573 0.093 281.6);
}

Tailwind CSS v4

@theme {
  --color-twinkle-night: #6f71ae;
  --color-twinkle-night-50: #f1f2ff;
  --color-twinkle-night-100: #e3e5ff;
  --color-twinkle-night-200: #ced0fc;
  --color-twinkle-night-300: #b1b2e6;
  --color-twinkle-night-400: #9598d5;
  --color-twinkle-night-500: #7c7ec3;
  --color-twinkle-night-600: #696ba4;
  --color-twinkle-night-700: #545584;
  --color-twinkle-night-800: #3c3f62;
  --color-twinkle-night-900: #292b45;
  --color-twinkle-night-950: #17182d;
}

SCSS

$twinkle-night: #6f71ae;
$twinkle-night-rgb: 111, 113, 174;
$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);
}