#1CAABC

CSS

:root {
  --true-sky-blue: #1caabc;
  --true-sky-blue-rgb: 28 170 188;
  --true-sky-blue-oklch: oklch(0.677 0.112 208.6);
}

.element {
  color: var(--true-sky-blue);
  background-color: hsl(187 74% 42%);
  border-color: oklch(0.677 0.112 208.6);
}

Tailwind CSS v4

@theme {
  --color-true-sky-blue: #1caabc;
  --color-true-sky-blue-50: #d1ffff;
  --color-true-sky-blue-100: #bdf3fd;
  --color-true-sky-blue-200: #9be2ef;
  --color-true-sky-blue-300: #6dc7d8;
  --color-true-sky-blue-400: #37b0c1;
  --color-true-sky-blue-500: #0099ad;
  --color-true-sky-blue-600: #008292;
  --color-true-sky-blue-700: #006875;
  --color-true-sky-blue-800: #004d56;
  --color-true-sky-blue-900: #00353c;
  --color-true-sky-blue-950: #002026;
}

SCSS

$true-sky-blue: #1caabc;
$true-sky-blue-rgb: 28, 170, 188;
$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);
}