#ACBBDC

CSS

:root {
  --over-the-moon: #acbbdc;
  --over-the-moon-rgb: 172 187 220;
  --over-the-moon-oklch: oklch(0.791 0.05 265.9);
}

.element {
  color: var(--over-the-moon);
  background-color: hsl(221 41% 77%);
  border-color: oklch(0.791 0.05 265.9);
}

Tailwind CSS v4

@theme {
  --color-over-the-moon: #acbbdc;
  --color-over-the-moon-50: #eff5ff;
  --color-over-the-moon-100: #e1e8f9;
  --color-over-the-moon-200: #cbd4ea;
  --color-over-the-moon-300: #acb7d2;
  --color-over-the-moon-400: #919ebd;
  --color-over-the-moon-500: #7786a8;
  --color-over-the-moon-600: #65718e;
  --color-over-the-moon-700: #505b72;
  --color-over-the-moon-800: #3a4254;
  --color-over-the-moon-900: #272e3b;
  --color-over-the-moon-950: #161b25;
}

SCSS

$over-the-moon: #acbbdc;
$over-the-moon-rgb: 172, 187, 220;
$over-the-moon-light: mix(#fff, $over-the-moon, 20%);
$over-the-moon-dark: mix(#000, $over-the-moon, 20%);

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