#23A9C4

CSS

:root {
  --true-sky-blue: #23a9c4;
  --true-sky-blue-rgb: 35 169 196;
  --true-sky-blue-oklch: oklch(0.679 0.113 215.6);
}

.element {
  color: var(--true-sky-blue);
  background-color: hsl(190 70% 45%);
  border-color: oklch(0.679 0.113 215.6);
}

Tailwind CSS v4

@theme {
  --color-true-sky-blue: #23a9c4;
  --color-true-sky-blue-50: #d2feff;
  --color-true-sky-blue-100: #bef2ff;
  --color-true-sky-blue-200: #9ce1f4;
  --color-true-sky-blue-300: #6ec6de;
  --color-true-sky-blue-400: #3aafc9;
  --color-true-sky-blue-500: #0098b5;
  --color-true-sky-blue-600: #008099;
  --color-true-sky-blue-700: #00677b;
  --color-true-sky-blue-800: #004c5a;
  --color-true-sky-blue-900: #00353f;
  --color-true-sky-blue-950: #002028;
}

SCSS

$true-sky-blue: #23a9c4;
$true-sky-blue-rgb: 35, 169, 196;
$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);
}