#030260

CSS

:root {
  --alone-in-the-dark: #030260;
  --alone-in-the-dark-rgb: 3 2 96;
  --alone-in-the-dark-oklch: oklch(0.225 0.15 265.7);
}

.element {
  color: var(--alone-in-the-dark);
  background-color: hsl(241 96% 19%);
  border-color: oklch(0.225 0.15 265.7);
}

Tailwind CSS v4

@theme {
  --color-alone-in-the-dark: #030260;
  --color-alone-in-the-dark-50: #e2f5ff;
  --color-alone-in-the-dark-100: #d2e7ff;
  --color-alone-in-the-dark-200: #b8d3ff;
  --color-alone-in-the-dark-300: #96b4ff;
  --color-alone-in-the-dark-400: #749af7;
  --color-alone-in-the-dark-500: #567fe9;
  --color-alone-in-the-dark-600: #496cc4;
  --color-alone-in-the-dark-700: #3a569e;
  --color-alone-in-the-dark-800: #274076;
  --color-alone-in-the-dark-900: #1a2c53;
  --color-alone-in-the-dark-950: #0b1938;
}

SCSS

$alone-in-the-dark: #030260;
$alone-in-the-dark-rgb: 3, 2, 96;
$alone-in-the-dark-light: mix(#fff, $alone-in-the-dark, 20%);
$alone-in-the-dark-dark: mix(#000, $alone-in-the-dark, 20%);

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