#342858

CSS

:root {
  --purple-noir: #342858;
  --purple-noir-rgb: 52 40 88;
  --purple-noir-oklch: oklch(0.317 0.083 292.5);
}

.element {
  color: var(--purple-noir);
  background-color: hsl(255 38% 25%);
  border-color: oklch(0.317 0.083 292.5);
}

Tailwind CSS v4

@theme {
  --color-purple-noir: #342858;
  --color-purple-noir-50: #f6f1ff;
  --color-purple-noir-100: #e9e3ff;
  --color-purple-noir-200: #d6cef5;
  --color-purple-noir-300: #bab0de;
  --color-purple-noir-400: #9f96cc;
  --color-purple-noir-500: #887cb9;
  --color-purple-noir-600: #73699c;
  --color-purple-noir-700: #5c547d;
  --color-purple-noir-800: #423d5d;
  --color-purple-noir-900: #2e2a41;
  --color-purple-noir-950: #1a182a;
}

SCSS

$purple-noir: #342858;
$purple-noir-rgb: 52, 40, 88;
$purple-noir-light: mix(#fff, $purple-noir, 20%);
$purple-noir-dark: mix(#000, $purple-noir, 20%);

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