#AFBDDC

CSS

:root {
  --over-the-moon: #afbddc;
  --over-the-moon-rgb: 175 189 220;
  --over-the-moon-oklch: oklch(0.798 0.047 266.1);
}

.element {
  color: var(--over-the-moon);
  background-color: hsl(221 39% 77%);
  border-color: oklch(0.798 0.047 266.1);
}

Tailwind CSS v4

@theme {
  --color-over-the-moon: #afbddc;
  --color-over-the-moon-50: #eff5ff;
  --color-over-the-moon-100: #e1e8f8;
  --color-over-the-moon-200: #ccd4e9;
  --color-over-the-moon-300: #adb7d0;
  --color-over-the-moon-400: #929ebb;
  --color-over-the-moon-500: #7886a6;
  --color-over-the-moon-600: #65718c;
  --color-over-the-moon-700: #515b70;
  --color-over-the-moon-800: #3a4253;
  --color-over-the-moon-900: #282e3a;
  --color-over-the-moon-950: #161b24;
}

SCSS

$over-the-moon: #afbddc;
$over-the-moon-rgb: 175, 189, 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);
}