Grey Blue

CSS

:root {
  --grey-blue: #77a1b5;
  --grey-blue-rgb: 119 161 181;
  --grey-blue-oklch: oklch(0.686 0.054 228.9);
}

.element {
  color: var(--grey-blue);
  background-color: hsl(199 30% 59%);
  border-color: oklch(0.686 0.054 228.9);
}

Tailwind CSS v4

@theme {
  --color-grey-blue: #77a1b5;
  --color-grey-blue-50: #e6f8ff;
  --color-grey-blue-100: #d7ecf7;
  --color-grey-blue-200: #bed9e8;
  --color-grey-blue-300: #9cbdce;
  --color-grey-blue-400: #7da5b8;
  --color-grey-blue-500: #5f8da3;
  --color-grey-blue-600: #51788a;
  --color-grey-blue-700: #41606e;
  --color-grey-blue-800: #2e4651;
  --color-grey-blue-900: #1f3138;
  --color-grey-blue-950: #0f1d23;
}

SCSS

$grey-blue: #77a1b5;
$grey-blue-rgb: 119, 161, 181;
$grey-blue-light: mix(#fff, $grey-blue, 20%);
$grey-blue-dark: mix(#000, $grey-blue, 20%);

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