#5274C4

CSS

:root {
  --serenity-s-reign: #5274c4;
  --serenity-s-reign-rgb: 82 116 196;
  --serenity-s-reign-oklch: oklch(0.572 0.13 265.2);
}

.element {
  color: var(--serenity-s-reign);
  background-color: hsl(222 49% 55%);
  border-color: oklch(0.572 0.13 265.2);
}

Tailwind CSS v4

@theme {
  --color-serenity-s-reign: #5274c4;
  --color-serenity-s-reign-50: #e5f5ff;
  --color-serenity-s-reign-100: #d5e7ff;
  --color-serenity-s-reign-200: #bcd3ff;
  --color-serenity-s-reign-300: #9ab5fb;
  --color-serenity-s-reign-400: #799ceb;
  --color-serenity-s-reign-500: #5c82dc;
  --color-serenity-s-reign-600: #4e6eb9;
  --color-serenity-s-reign-700: #3e5895;
  --color-serenity-s-reign-800: #2a416f;
  --color-serenity-s-reign-900: #1c2d4e;
  --color-serenity-s-reign-950: #0d1934;
}

SCSS

$serenity-s-reign: #5274c4;
$serenity-s-reign-rgb: 82, 116, 196;
$serenity-s-reign-light: mix(#fff, $serenity-s-reign, 20%);
$serenity-s-reign-dark: mix(#000, $serenity-s-reign, 20%);

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