#99BDE8

CSS

:root {
  --adrift-on-the-nile: #99bde8;
  --adrift-on-the-nile-rgb: 153 189 232;
  --adrift-on-the-nile-oklch: oklch(0.787 0.073 253.2);
}

.element {
  color: var(--adrift-on-the-nile);
  background-color: hsl(213 63% 75%);
  border-color: oklch(0.787 0.073 253.2);
}

Tailwind CSS v4

@theme {
  --color-adrift-on-the-nile: #99bde8;
  --color-adrift-on-the-nile-50: #e8f7ff;
  --color-adrift-on-the-nile-100: #d8eaff;
  --color-adrift-on-the-nile-200: #c0d6f4;
  --color-adrift-on-the-nile-300: #9fbadd;
  --color-adrift-on-the-nile-400: #80a1c9;
  --color-adrift-on-the-nile-500: #6389b6;
  --color-adrift-on-the-nile-600: #547499;
  --color-adrift-on-the-nile-700: #435d7b;
  --color-adrift-on-the-nile-800: #2f445b;
  --color-adrift-on-the-nile-900: #202f40;
  --color-adrift-on-the-nile-950: #0f1c29;
}

SCSS

$adrift-on-the-nile: #99bde8;
$adrift-on-the-nile-rgb: 153, 189, 232;
$adrift-on-the-nile-light: mix(#fff, $adrift-on-the-nile, 20%);
$adrift-on-the-nile-dark: mix(#000, $adrift-on-the-nile, 20%);

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