#2A495D

CSS

:root {
  --one-year-of-rain: #2a495d;
  --one-year-of-rain-rgb: 42 73 93;
  --one-year-of-rain-oklch: oklch(0.39 0.05 238.2);
}

.element {
  color: var(--one-year-of-rain);
  background-color: hsl(204 38% 26%);
  border-color: oklch(0.39 0.05 238.2);
}

Tailwind CSS v4

@theme {
  --color-one-year-of-rain: #2a495d;
  --color-one-year-of-rain-50: #e9f7ff;
  --color-one-year-of-rain-100: #daebf7;
  --color-one-year-of-rain-200: #c2d8e8;
  --color-one-year-of-rain-300: #a1bbcf;
  --color-one-year-of-rain-400: #83a3b9;
  --color-one-year-of-rain-500: #678ba4;
  --color-one-year-of-rain-600: #57768b;
  --color-one-year-of-rain-700: #465e6f;
  --color-one-year-of-rain-800: #324552;
  --color-one-year-of-rain-900: #223039;
  --color-one-year-of-rain-950: #111c23;
}

SCSS

$one-year-of-rain: #2a495d;
$one-year-of-rain-rgb: 42, 73, 93;
$one-year-of-rain-light: mix(#fff, $one-year-of-rain, 20%);
$one-year-of-rain-dark: mix(#000, $one-year-of-rain, 20%);

.element {
  color: $one-year-of-rain;
  box-shadow: 0 0 0 2px rgba($one-year-of-rain, 0.35);
}