#40A7C2

CSS

:root {
  --true-sky-blue: #40a7c2;
  --true-sky-blue-rgb: 64 167 194;
  --true-sky-blue-oklch: oklch(0.68 0.101 218.5);
}

.element {
  color: var(--true-sky-blue);
  background-color: hsl(192 52% 51%);
  border-color: oklch(0.68 0.101 218.5);
}

Tailwind CSS v4

@theme {
  --color-true-sky-blue: #40a7c2;
  --color-true-sky-blue-50: #d7fdff;
  --color-true-sky-blue-100: #c4f0ff;
  --color-true-sky-blue-200: #a4dff3;
  --color-true-sky-blue-300: #7ac4dc;
  --color-true-sky-blue-400: #4eadc6;
  --color-true-sky-blue-500: #0495b3;
  --color-true-sky-blue-600: #0f7e97;
  --color-true-sky-blue-700: #0e6579;
  --color-true-sky-blue-800: #054b59;
  --color-true-sky-blue-900: #04343e;
  --color-true-sky-blue-950: #001f27;
}

SCSS

$true-sky-blue: #40a7c2;
$true-sky-blue-rgb: 64, 167, 194;
$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);
}