#1C6DC0

CSS

:root {
  --matt-blue: #1c6dc0;
  --matt-blue-rgb: 28 109 192;
  --matt-blue-oklch: oklch(0.533 0.15 253.3);
}

.element {
  color: var(--matt-blue);
  background-color: hsl(210 75% 43%);
  border-color: oklch(0.533 0.15 253.3);
}

Tailwind CSS v4

@theme {
  --color-matt-blue: #1c6dc0;
  --color-matt-blue-50: #d9f8ff;
  --color-matt-blue-100: #c7ebff;
  --color-matt-blue-200: #a9d8ff;
  --color-matt-blue-300: #82baff;
  --color-matt-blue-400: #59a1f4;
  --color-matt-blue-500: #2f87e6;
  --color-matt-blue-600: #2a73c2;
  --color-matt-blue-700: #215c9c;
  --color-matt-blue-800: #114474;
  --color-matt-blue-900: #0b2f52;
  --color-matt-blue-950: #001b37;
}

SCSS

$matt-blue: #1c6dc0;
$matt-blue-rgb: 28, 109, 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);
}