#4DA6BE

CSS

:root {
  --true-sky-blue: #4da6be;
  --true-sky-blue-rgb: 77 166 190;
  --true-sky-blue-oklch: oklch(0.68 0.091 218.1);
}

.element {
  color: var(--true-sky-blue);
  background-color: hsl(193 47% 52%);
  border-color: oklch(0.68 0.091 218.1);
}

Tailwind CSS v4

@theme {
  --color-true-sky-blue: #4da6be;
  --color-true-sky-blue-50: #dafcff;
  --color-true-sky-blue-100: #c7f0fd;
  --color-true-sky-blue-200: #a9def0;
  --color-true-sky-blue-300: #81c3d8;
  --color-true-sky-blue-400: #59acc2;
  --color-true-sky-blue-500: #2894ae;
  --color-true-sky-blue-600: #257d93;
  --color-true-sky-blue-700: #1e6476;
  --color-true-sky-blue-800: #124a57;
  --color-true-sky-blue-900: #0c333c;
  --color-true-sky-blue-950: #001f26;
}

SCSS

$true-sky-blue: #4da6be;
$true-sky-blue-rgb: 77, 166, 190;
$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);
}