#0D69D5

CSS

:root {
  --matt-blue: #0d69d5;
  --matt-blue-rgb: 13 105 213;
  --matt-blue-oklch: oklch(0.537 0.184 257.1);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(212 88% 44%);
  border-color: oklch(0.537 0.184 257.1);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #0d69d5;
  --color-matt-blue-50: #d6f7ff;
  --color-matt-blue-100: #c3eaff;
  --color-matt-blue-200: #a5d6ff;
  --color-matt-blue-300: #7cb8ff;
  --color-matt-blue-400: #509eff;
  --color-matt-blue-500: #2082fc;
  --color-matt-blue-600: #1e6ed5;
  --color-matt-blue-700: #1858ab;
  --color-matt-blue-800: #064180;
  --color-matt-blue-900: #052d5a;
  --color-matt-blue-950: #00193d;
}

SCSS

$matt-blue: #0d69d5;
$matt-blue-rgb: 13, 105, 213;
$matt-blue-light: mix(#fff, $matt-blue, 20%);
$matt-blue-dark: mix(#000, $matt-blue, 20%);

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