#00AAC6

CSS

:root {
  --true-sky-blue: #00aac6;
  --true-sky-blue-rgb: 0 170 198;
  --true-sky-blue-oklch: oklch(0.679 0.12 215);
}

.element {
  color: var(--true-sky-blue);
  background-color: hsl(188 100% 39%);
  border-color: oklch(0.679 0.12 215);
}

Tailwind CSS v4

@theme {
  --color-true-sky-blue: #00aac6;
  --color-true-sky-blue-50: #d0feff;
  --color-true-sky-blue-100: #bbf3ff;
  --color-true-sky-blue-200: #98e2f6;
  --color-true-sky-blue-300: #68c7df;
  --color-true-sky-blue-400: #2cb0ca;
  --color-true-sky-blue-500: #0099b7;
  --color-true-sky-blue-600: #00819b;
  --color-true-sky-blue-700: #00677c;
  --color-true-sky-blue-800: #004c5b;
  --color-true-sky-blue-900: #003540;
  --color-true-sky-blue-950: #002029;
}

SCSS

$true-sky-blue: #00aac6;
$true-sky-blue-rgb: 0, 170, 198;
$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);
}