#126EF2

CSS

:root {
  --deep-sky-blue: #126ef2;
  --deep-sky-blue-rgb: 18 110 242;
  --deep-sky-blue-oklch: oklch(0.57 0.214 259.4);
}

.element {
  color: var(--deep-sky-blue);
  background-color: hsl(215 90% 51%);
  border-color: oklch(0.57 0.214 259.4);
}

Tailwind CSS v4

@theme {
  --color-deep-sky-blue: #126ef2;
  --color-deep-sky-blue-50: #d3f6ff;
  --color-deep-sky-blue-100: #c0e9ff;
  --color-deep-sky-blue-200: #a0d4ff;
  --color-deep-sky-blue-300: #78b5ff;
  --color-deep-sky-blue-400: #499aff;
  --color-deep-sky-blue-500: #127bff;
  --color-deep-sky-blue-600: #1469e5;
  --color-deep-sky-blue-700: #1154b8;
  --color-deep-sky-blue-800: #003e8a;
  --color-deep-sky-blue-900: #012b62;
  --color-deep-sky-blue-950: #001743;
}

SCSS

$deep-sky-blue: #126ef2;
$deep-sky-blue-rgb: 18, 110, 242;
$deep-sky-blue-light: mix(#fff, $deep-sky-blue, 20%);
$deep-sky-blue-dark: mix(#000, $deep-sky-blue, 20%);

.element {
  color: $deep-sky-blue;
  box-shadow: 0 0 0 2px rgba($deep-sky-blue, 0.35);
}