#2E6DB9

CSS

:root {
  --matt-blue: #2e6db9;
  --matt-blue-rgb: 46 109 185;
  --matt-blue-oklch: oklch(0.533 0.136 255);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(213 60% 45%);
  border-color: oklch(0.533 0.136 255);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #2e6db9;
  --color-matt-blue-50: #ddf7ff;
  --color-matt-blue-100: #cceaff;
  --color-matt-blue-200: #afd7ff;
  --color-matt-blue-300: #8abafc;
  --color-matt-blue-400: #65a1ed;
  --color-matt-blue-500: #4087de;
  --color-matt-blue-600: #3872bb;
  --color-matt-blue-700: #2c5c96;
  --color-matt-blue-800: #1b4470;
  --color-matt-blue-900: #122f4f;
  --color-matt-blue-950: #041b34;
}

SCSS

$matt-blue: #2e6db9;
$matt-blue-rgb: 46, 109, 185;
$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);
}