#9ED6F0

CSS

:root {
  --over-the-sky: #9ed6f0;
  --over-the-sky-rgb: 158 214 240;
  --over-the-sky-oklch: oklch(0.846 0.068 228.3);
}

.element {
  color: var(--over-the-sky);
  background-color: hsl(199 73% 78%);
  border-color: oklch(0.846 0.068 228.3);
}

Tailwind CSS v4

@theme {
  --color-over-the-sky: #9ed6f0;
  --color-over-the-sky-50: #e2f9ff;
  --color-over-the-sky-100: #d2edfb;
  --color-over-the-sky-200: #b8daec;
  --color-over-the-sky-300: #94bfd4;
  --color-over-the-sky-400: #73a7be;
  --color-over-the-sky-500: #538faa;
  --color-over-the-sky-600: #477990;
  --color-over-the-sky-700: #386173;
  --color-over-the-sky-800: #274754;
  --color-over-the-sky-900: #1a313b;
  --color-over-the-sky-950: #0a1d25;
}

SCSS

$over-the-sky: #9ed6f0;
$over-the-sky-rgb: 158, 214, 240;
$over-the-sky-light: mix(#fff, $over-the-sky, 20%);
$over-the-sky-dark: mix(#000, $over-the-sky, 20%);

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