#B44C30

CSS

:root {
  --crimson-boy: #b44c30;
  --crimson-boy-rgb: 180 76 48;
  --crimson-boy-oklch: oklch(0.548 0.142 36);
}

.element {
  color: var(--crimson-boy);
  background-color: hsl(13 58% 45%);
  border-color: oklch(0.548 0.142 36);
}

Tailwind CSS v4

@theme {
  --color-crimson-boy: #b44c30;
  --color-crimson-boy-50: #ffe8d8;
  --color-crimson-boy-100: #ffd8c6;
  --color-crimson-boy-200: #ffc0a8;
  --color-crimson-boy-300: #f69d82;
  --color-crimson-boy-400: #e57d61;
  --color-crimson-boy-500: #d35d3d;
  --color-crimson-boy-600: #b24f35;
  --color-crimson-boy-700: #8f3f2a;
  --color-crimson-boy-800: #6b2d1f;
  --color-crimson-boy-900: #4b1e14;
  --color-crimson-boy-950: #310d06;
}

SCSS

$crimson-boy: #b44c30;
$crimson-boy-rgb: 180, 76, 48;
$crimson-boy-light: mix(#fff, $crimson-boy, 20%);
$crimson-boy-dark: mix(#000, $crimson-boy, 20%);

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