#236CF5

CSS

:root {
  --blue-ribbon: #236cf5;
  --blue-ribbon-rgb: 35 108 245;
  --blue-ribbon-oklch: oklch(0.571 0.218 261.6);
}

.element {
  color: var(--blue-ribbon);
  background-color: hsl(219 91% 55%);
  border-color: oklch(0.571 0.218 261.6);
}

Tailwind CSS v4

@theme {
  --color-blue-ribbon: #236cf5;
  --color-blue-ribbon-50: #d5f6ff;
  --color-blue-ribbon-100: #c2e8ff;
  --color-blue-ribbon-200: #a4d3ff;
  --color-blue-ribbon-300: #7cb3ff;
  --color-blue-ribbon-400: #5198ff;
  --color-blue-ribbon-500: #2679ff;
  --color-blue-ribbon-600: #2267e7;
  --color-blue-ribbon-700: #1b52ba;
  --color-blue-ribbon-800: #083d8c;
  --color-blue-ribbon-900: #052a63;
  --color-blue-ribbon-950: #001644;
}

SCSS

$blue-ribbon: #236cf5;
$blue-ribbon-rgb: 35, 108, 245;
$blue-ribbon-light: mix(#fff, $blue-ribbon, 20%);
$blue-ribbon-dark: mix(#000, $blue-ribbon, 20%);

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