#D54048

CSS

:root {
  --poppy-red: #d54048;
  --poppy-red-rgb: 213 64 72;
  --poppy-red-oklch: oklch(0.59 0.185 22.1);
}

.element {
  color: var(--poppy-red);
  background-color: hsl(357 64% 54%);
  border-color: oklch(0.59 0.185 22.1);
}

Tailwind CSS v4

@theme {
  --color-poppy-red: #d54048;
  --color-poppy-red-50: #ffe1db;
  --color-poppy-red-100: #ffd0ca;
  --color-poppy-red-200: #ffb4ad;
  --color-poppy-red-300: #ff8e88;
  --color-poppy-red-400: #f8696b;
  --color-poppy-red-500: #e73f4a;
  --color-poppy-red-600: #c33740;
  --color-poppy-red-700: #9d2c32;
  --color-poppy-red-800: #751e26;
  --color-poppy-red-900: #531419;
  --color-poppy-red-950: #37040a;
}

SCSS

$poppy-red: #d54048;
$poppy-red-rgb: 213, 64, 72;
$poppy-red-light: mix(#fff, $poppy-red, 20%);
$poppy-red-dark: mix(#000, $poppy-red, 20%);

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