#345AA5

CSS

:root {
  --blasphemous-blue: #345aa5;
  --blasphemous-blue-rgb: 52 90 165;
  --blasphemous-blue-oklch: oklch(0.48 0.128 262.4);
}

.element {
  color: var(--blasphemous-blue);
  background-color: hsl(220 52% 43%);
  border-color: oklch(0.48 0.128 262.4);
}

Tailwind CSS v4

@theme {
  --color-blasphemous-blue: #345aa5;
  --color-blasphemous-blue-50: #e3f6ff;
  --color-blasphemous-blue-100: #d3e8ff;
  --color-blasphemous-blue-200: #b9d4ff;
  --color-blasphemous-blue-300: #96b7fa;
  --color-blasphemous-blue-400: #759dea;
  --color-blasphemous-blue-500: #5683db;
  --color-blasphemous-blue-600: #4a6fb8;
  --color-blasphemous-blue-700: #3b5994;
  --color-blasphemous-blue-800: #27426e;
  --color-blasphemous-blue-900: #1a2d4e;
  --color-blasphemous-blue-950: #0b1a34;
}

SCSS

$blasphemous-blue: #345aa5;
$blasphemous-blue-rgb: 52, 90, 165;
$blasphemous-blue-light: mix(#fff, $blasphemous-blue, 20%);
$blasphemous-blue-dark: mix(#000, $blasphemous-blue, 20%);

.element {
  color: $blasphemous-blue;
  box-shadow: 0 0 0 2px rgba($blasphemous-blue, 0.35);
}