#6E70A3

CSS

:root {
  --twinkle-night: #6e70a3;
  --twinkle-night-rgb: 110 112 163;
  --twinkle-night-oklch: oklch(0.564 0.079 281.8);
}

.element {
  color: var(--twinkle-night);
  background-color: hsl(238 22% 54%);
  border-color: oklch(0.564 0.079 281.8);
}

Tailwind CSS v4

@theme {
  --color-twinkle-night: #6e70a3;
  --color-twinkle-night-50: #f2f3ff;
  --color-twinkle-night-100: #e4e5ff;
  --color-twinkle-night-200: #cfd0f6;
  --color-twinkle-night-300: #b2b3df;
  --color-twinkle-night-400: #9699cc;
  --color-twinkle-night-500: #7e80b9;
  --color-twinkle-night-600: #6a6c9c;
  --color-twinkle-night-700: #55577d;
  --color-twinkle-night-800: #3d3f5d;
  --color-twinkle-night-900: #2a2c41;
  --color-twinkle-night-950: #17192a;
}

SCSS

$twinkle-night: #6e70a3;
$twinkle-night-rgb: 110, 112, 163;
$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);
}