#5B69A2

CSS

:root {
  --bellflower: #5b69a2;
  --bellflower-rgb: 91 105 162;
  --bellflower-oklch: oklch(0.534 0.091 272.5);
}

.element {
  color: var(--bellflower);
  background-color: hsl(228 28% 50%);
  border-color: oklch(0.534 0.091 272.5);
}

Tailwind CSS v4

@theme {
  --color-bellflower: #5b69a2;
  --color-bellflower-50: #edf4ff;
  --color-bellflower-100: #dee6ff;
  --color-bellflower-200: #c8d2fc;
  --color-bellflower-300: #a9b4e7;
  --color-bellflower-400: #8c9bd5;
  --color-bellflower-500: #7282c3;
  --color-bellflower-600: #606ea4;
  --color-bellflower-700: #4d5884;
  --color-bellflower-800: #364162;
  --color-bellflower-900: #252c45;
  --color-bellflower-950: #14192d;
}

SCSS

$bellflower: #5b69a2;
$bellflower-rgb: 91, 105, 162;
$bellflower-light: mix(#fff, $bellflower, 20%);
$bellflower-dark: mix(#000, $bellflower, 20%);

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