#2E77D0

CSS

:root {
  --fading-night: #2e77d0;
  --fading-night-rgb: 46 119 208;
  --fading-night-oklch: oklch(0.57 0.155 255.5);
}

.element {
  color: var(--fading-night);
  background-color: hsl(213 64% 50%);
  border-color: oklch(0.57 0.155 255.5);
}

Tailwind CSS v4

@theme {
  --color-fading-night: #2e77d0;
  --color-fading-night-50: #daf7ff;
  --color-fading-night-100: #c8eaff;
  --color-fading-night-200: #aad7ff;
  --color-fading-night-300: #84b9ff;
  --color-fading-night-400: #5ca0f8;
  --color-fading-night-500: #3386ea;
  --color-fading-night-600: #2d71c5;
  --color-fading-night-700: #245b9e;
  --color-fading-night-800: #134376;
  --color-fading-night-900: #0c2e53;
  --color-fading-night-950: #011a38;
}

SCSS

$fading-night: #2e77d0;
$fading-night-rgb: 46, 119, 208;
$fading-night-light: mix(#fff, $fading-night, 20%);
$fading-night-dark: mix(#000, $fading-night, 20%);

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