#B5C5F6

CSS

:root {
  --sky-high: #b5c5f6;
  --sky-high-rgb: 181 197 246;
  --sky-high-oklch: oklch(0.828 0.071 270.7);
}

.element {
  color: var(--sky-high);
  background-color: hsl(225 78% 84%);
  border-color: oklch(0.828 0.071 270.7);
}

Tailwind CSS v4

@theme {
  --color-sky-high: #b5c5f6;
  --color-sky-high-50: #eef4ff;
  --color-sky-high-100: #dfe7ff;
  --color-sky-high-200: #cad3f4;
  --color-sky-high-300: #abb6dd;
  --color-sky-high-400: #8e9dc9;
  --color-sky-high-500: #7484b6;
  --color-sky-high-600: #62709a;
  --color-sky-high-700: #4f597b;
  --color-sky-high-800: #38415b;
  --color-sky-high-900: #262d40;
  --color-sky-high-950: #151a29;
}

SCSS

$sky-high: #b5c5f6;
$sky-high-rgb: 181, 197, 246;
$sky-high-light: mix(#fff, $sky-high, 20%);
$sky-high-dark: mix(#000, $sky-high, 20%);

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