#1E76AE

CSS

:root {
  --brilliant-blue: #1e76ae;
  --brilliant-blue-rgb: 30 118 174;
  --brilliant-blue-oklch: oklch(0.543 0.118 242.5);
}

.element {
  color: var(--brilliant-blue);
  background-color: hsl(203 71% 40%);
  border-color: oklch(0.543 0.118 242.5);
}

Tailwind CSS v4

@theme {
  --color-brilliant-blue: #1e76ae;
  --color-brilliant-blue-50: #dafaff;
  --color-brilliant-blue-100: #c8edff;
  --color-brilliant-blue-200: #aadaff;
  --color-brilliant-blue-300: #82bef0;
  --color-brilliant-blue-400: #5aa6de;
  --color-brilliant-blue-500: #2d8ecd;
  --color-brilliant-blue-600: #2978ad;
  --color-brilliant-blue-700: #20608b;
  --color-brilliant-blue-800: #124767;
  --color-brilliant-blue-900: #0c3148;
  --color-brilliant-blue-950: #001d2f;
}

SCSS

$brilliant-blue: #1e76ae;
$brilliant-blue-rgb: 30, 118, 174;
$brilliant-blue-light: mix(#fff, $brilliant-blue, 20%);
$brilliant-blue-dark: mix(#000, $brilliant-blue, 20%);

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