#E51C14

CSS

:root {
  --miyamoto-red: #e51c14;
  --miyamoto-red-rgb: 229 28 20;
  --miyamoto-red-oklch: oklch(0.587 0.229 29.1);
}

.element {
  color: var(--miyamoto-red);
  background-color: hsl(2 84% 49%);
  border-color: oklch(0.587 0.229 29.1);
}

Tailwind CSS v4

@theme {
  --color-miyamoto-red: #e51c14;
  --color-miyamoto-red-50: #ffddcd;
  --color-miyamoto-red-100: #ffcbb9;
  --color-miyamoto-red-200: #ffad97;
  --color-miyamoto-red-300: #ff836b;
  --color-miyamoto-red-400: #ff5746;
  --color-miyamoto-red-500: #fa0806;
  --color-miyamoto-red-600: #d3140d;
  --color-miyamoto-red-700: #aa120c;
  --color-miyamoto-red-800: #7f080d;
  --color-miyamoto-red-900: #5a0708;
  --color-miyamoto-red-950: #3d0000;
}

SCSS

$miyamoto-red: #e51c14;
$miyamoto-red-rgb: 229, 28, 20;
$miyamoto-red-light: mix(#fff, $miyamoto-red, 20%);
$miyamoto-red-dark: mix(#000, $miyamoto-red, 20%);

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