#376AC0

CSS

:root {
  --matt-blue: #376ac0;
  --matt-blue-rgb: 55 106 192;
  --matt-blue-oklch: oklch(0.534 0.146 260.2);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(218 55% 48%);
  border-color: oklch(0.534 0.146 260.2);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #376ac0;
  --color-matt-blue-50: #dff6ff;
  --color-matt-blue-100: #cee9ff;
  --color-matt-blue-200: #b3d5ff;
  --color-matt-blue-300: #8fb7ff;
  --color-matt-blue-400: #6a9ef4;
  --color-matt-blue-500: #4983e5;
  --color-matt-blue-600: #3f6fc1;
  --color-matt-blue-700: #32599b;
  --color-matt-blue-800: #204274;
  --color-matt-blue-900: #152d52;
  --color-matt-blue-950: #071a37;
}

SCSS

$matt-blue: #376ac0;
$matt-blue-rgb: 55, 106, 192;
$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);
}