#3F6E77

CSS

:root {
  --winter-storm: #3f6e77;
  --winter-storm-rgb: 63 110 119;
  --winter-storm-oklch: oklch(0.508 0.053 211.2);
}

.element {
  color: var(--winter-storm);
  background-color: hsl(190 31% 36%);
  border-color: oklch(0.508 0.053 211.2);
}

Tailwind CSS v4

@theme {
  --color-winter-storm: #3f6e77;
  --color-winter-storm-50: #e5fafe;
  --color-winter-storm-100: #d5edf3;
  --color-winter-storm-200: #bbdbe2;
  --color-winter-storm-300: #99bfc8;
  --color-winter-storm-400: #7aa7b0;
  --color-winter-storm-500: #5b909a;
  --color-winter-storm-600: #4d7a82;
  --color-winter-storm-700: #3e6168;
  --color-winter-storm-800: #2c484c;
  --color-winter-storm-900: #1d3235;
  --color-winter-storm-950: #0d1e20;
}

SCSS

$winter-storm: #3f6e77;
$winter-storm-rgb: 63, 110, 119;
$winter-storm-light: mix(#fff, $winter-storm, 20%);
$winter-storm-dark: mix(#000, $winter-storm, 20%);

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