#0075DC

CSS

:root {
  --fading-night: #0075dc;
  --fading-night-rgb: 0 117 220;
  --fading-night-oklch: oklch(0.567 0.18 253.9);
}

.element {
  color: var(--fading-night);
  background-color: hsl(208 100% 43%);
  border-color: oklch(0.567 0.18 253.9);
}

Tailwind CSS v4

@theme {
  --color-fading-night: #0075dc;
  --color-fading-night-50: #d4f8ff;
  --color-fading-night-100: #c1ebff;
  --color-fading-night-200: #a1d7ff;
  --color-fading-night-300: #77baff;
  --color-fading-night-400: #48a0ff;
  --color-fading-night-500: #0085f9;
  --color-fading-night-600: #0971d1;
  --color-fading-night-700: #095aa8;
  --color-fading-night-800: #00437e;
  --color-fading-night-900: #002e59;
  --color-fading-night-950: #001a3c;
}

SCSS

$fading-night: #0075dc;
$fading-night-rgb: 0, 117, 220;
$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);
}