#4D4A77

CSS

:root {
  --tangent-periwinkle: #4d4a77;
  --tangent-periwinkle-rgb: 77 74 119;
  --tangent-periwinkle-oklch: oklch(0.432 0.073 285.9);
}

.element {
  color: var(--tangent-periwinkle);
  background-color: hsl(244 23% 38%);
  border-color: oklch(0.432 0.073 285.9);
}

Tailwind CSS v4

@theme {
  --color-tangent-periwinkle: #4d4a77;
  --color-tangent-periwinkle-50: #f3f2ff;
  --color-tangent-periwinkle-100: #e6e5ff;
  --color-tangent-periwinkle-200: #d2d0f3;
  --color-tangent-periwinkle-300: #b5b2dc;
  --color-tangent-periwinkle-400: #9a99c9;
  --color-tangent-periwinkle-500: #827fb5;
  --color-tangent-periwinkle-600: #6e6c99;
  --color-tangent-periwinkle-700: #58567b;
  --color-tangent-periwinkle-800: #3f3f5b;
  --color-tangent-periwinkle-900: #2b2b40;
  --color-tangent-periwinkle-950: #191929;
}

SCSS

$tangent-periwinkle: #4d4a77;
$tangent-periwinkle-rgb: 77, 74, 119;
$tangent-periwinkle-light: mix(#fff, $tangent-periwinkle, 20%);
$tangent-periwinkle-dark: mix(#000, $tangent-periwinkle, 20%);

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