#3E6DAD

CSS

:root {
  --matt-blue: #3e6dad;
  --matt-blue-rgb: 62 109 173;
  --matt-blue-oklch: oklch(0.532 0.114 256.6);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(215 47% 46%);
  border-color: oklch(0.532 0.114 256.6);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #3e6dad;
  --color-matt-blue-50: #e2f7ff;
  --color-matt-blue-100: #d1eaff;
  --color-matt-blue-200: #b7d6ff;
  --color-matt-blue-300: #94b9f2;
  --color-matt-blue-400: #72a0e1;
  --color-matt-blue-500: #5287d0;
  --color-matt-blue-600: #4673b0;
  --color-matt-blue-700: #385c8d;
  --color-matt-blue-800: #254369;
  --color-matt-blue-900: #192f4a;
  --color-matt-blue-950: #091b30;
}

SCSS

$matt-blue: #3e6dad;
$matt-blue-rgb: 62, 109, 173;
$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);
}