#4FA6B9

CSS

:root {
  --true-sky-blue: #4fa6b9;
  --true-sky-blue-rgb: 79 166 185;
  --true-sky-blue-oklch: oklch(0.679 0.088 214);
}

.element {
  color: var(--true-sky-blue);
  background-color: hsl(191 43% 52%);
  border-color: oklch(0.679 0.088 214);
}

Tailwind CSS v4

@theme {
  --color-true-sky-blue: #4fa6b9;
  --color-true-sky-blue-50: #dafcff;
  --color-true-sky-blue-100: #c8f0fb;
  --color-true-sky-blue-200: #aadeec;
  --color-true-sky-blue-300: #82c3d4;
  --color-true-sky-blue-400: #5bacbe;
  --color-true-sky-blue-500: #2c95aa;
  --color-true-sky-blue-600: #287e8f;
  --color-true-sky-blue-700: #206573;
  --color-true-sky-blue-800: #144a54;
  --color-true-sky-blue-900: #0d343b;
  --color-true-sky-blue-950: #011f25;
}

SCSS

$true-sky-blue: #4fa6b9;
$true-sky-blue-rgb: 79, 166, 185;
$true-sky-blue-light: mix(#fff, $true-sky-blue, 20%);
$true-sky-blue-dark: mix(#000, $true-sky-blue, 20%);

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