#04035E

CSS

:root {
  --alone-in-the-dark: #04035e;
  --alone-in-the-dark-rgb: 4 3 94;
  --alone-in-the-dark-oklch: oklch(0.224 0.146 266.4);
}

.element {
  color: var(--alone-in-the-dark);
  background-color: hsl(241 94% 19%);
  border-color: oklch(0.224 0.146 266.4);
}

Tailwind CSS v4

@theme {
  --color-alone-in-the-dark: #04035e;
  --color-alone-in-the-dark-50: #e3f5ff;
  --color-alone-in-the-dark-100: #d3e7ff;
  --color-alone-in-the-dark-200: #bad2ff;
  --color-alone-in-the-dark-300: #98b4ff;
  --color-alone-in-the-dark-400: #769af5;
  --color-alone-in-the-dark-500: #597fe6;
  --color-alone-in-the-dark-600: #4c6cc2;
  --color-alone-in-the-dark-700: #3c569c;
  --color-alone-in-the-dark-800: #284075;
  --color-alone-in-the-dark-900: #1b2c52;
  --color-alone-in-the-dark-950: #0b1937;
}

SCSS

$alone-in-the-dark: #04035e;
$alone-in-the-dark-rgb: 4, 3, 94;
$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);
}