#C2D3D4

CSS

:root {
  --up-in-the-air: #c2d3d4;
  --up-in-the-air-rgb: 194 211 212;
  --up-in-the-air-oklch: oklch(0.854 0.018 201.1);
}

.element {
  color: var(--up-in-the-air);
  background-color: hsl(183 17% 80%);
  border-color: oklch(0.854 0.018 201.1);
}

Tailwind CSS v4

@theme {
  --color-up-in-the-air: #c2d3d4;
  --color-up-in-the-air-50: #eff7f7;
  --color-up-in-the-air-100: #e1eaea;
  --color-up-in-the-air-200: #ccd7d8;
  --color-up-in-the-air-300: #adbabb;
  --color-up-in-the-air-400: #92a2a3;
  --color-up-in-the-air-500: #798a8b;
  --color-up-in-the-air-600: #667576;
  --color-up-in-the-air-700: #525d5e;
  --color-up-in-the-air-800: #3b4445;
  --color-up-in-the-air-900: #292f2f;
  --color-up-in-the-air-950: #171c1c;
}

SCSS

$up-in-the-air: #c2d3d4;
$up-in-the-air-rgb: 194, 211, 212;
$up-in-the-air-light: mix(#fff, $up-in-the-air, 20%);
$up-in-the-air-dark: mix(#000, $up-in-the-air, 20%);

.element {
  color: $up-in-the-air;
  box-shadow: 0 0 0 2px rgba($up-in-the-air, 0.35);
}