#363F55

CSS

:root {
  --dark-stormy: #363f55;
  --dark-stormy-rgb: 54 63 85;
  --dark-stormy-oklch: oklch(0.369 0.04 267.2);
}

.element {
  color: var(--dark-stormy);
  background-color: hsl(223 22% 27%);
  border-color: oklch(0.369 0.04 267.2);
}

Tailwind CSS v4

@theme {
  --color-dark-stormy: #363f55;
  --color-dark-stormy-50: #f0f5ff;
  --color-dark-stormy-100: #e2e8f6;
  --color-dark-stormy-200: #cdd4e6;
  --color-dark-stormy-300: #afb7cd;
  --color-dark-stormy-400: #949eb7;
  --color-dark-stormy-500: #7a86a1;
  --color-dark-stormy-600: #687188;
  --color-dark-stormy-700: #535b6d;
  --color-dark-stormy-800: #3c4251;
  --color-dark-stormy-900: #292e38;
  --color-dark-stormy-950: #171b23;
}

SCSS

$dark-stormy: #363f55;
$dark-stormy-rgb: 54, 63, 85;
$dark-stormy-light: mix(#fff, $dark-stormy, 20%);
$dark-stormy-dark: mix(#000, $dark-stormy, 20%);

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