#0054EC

CSS

:root {
  --opulent-blue: #0054ec;
  --opulent-blue-rgb: 0 84 236;
  --opulent-blue-oklch: oklch(0.513 0.238 262);
}

.element {
  color: var(--opulent-blue);
  background-color: hsl(219 100% 46%);
  border-color: oklch(0.513 0.238 262);
}

Tailwind CSS v4

@theme {
  --color-opulent-blue: #0054ec;
  --color-opulent-blue-50: #d3f5ff;
  --color-opulent-blue-100: #c0e7ff;
  --color-opulent-blue-200: #a0d2ff;
  --color-opulent-blue-300: #78b1ff;
  --color-opulent-blue-400: #4a95ff;
  --color-opulent-blue-500: #1c74ff;
  --color-opulent-blue-600: #1a63f2;
  --color-opulent-blue-700: #154fc3;
  --color-opulent-blue-800: #003b92;
  --color-opulent-blue-900: #022868;
  --color-opulent-blue-950: #001548;
}

SCSS

$opulent-blue: #0054ec;
$opulent-blue-rgb: 0, 84, 236;
$opulent-blue-light: mix(#fff, $opulent-blue, 20%);
$opulent-blue-dark: mix(#000, $opulent-blue, 20%);

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