#1E71E3

CSS

:root {
  --deep-sky-blue: #1e71e3;
  --deep-sky-blue-rgb: 30 113 227;
  --deep-sky-blue-oklch: oklch(0.567 0.19 258.2);
}

.element {
  color: var(--deep-sky-blue);
  background-color: hsl(215 78% 50%);
  border-color: oklch(0.567 0.19 258.2);
}

Tailwind CSS v4

@theme {
  --color-deep-sky-blue: #1e71e3;
  --color-deep-sky-blue-50: #d6f7ff;
  --color-deep-sky-blue-100: #c3e9ff;
  --color-deep-sky-blue-200: #a5d5ff;
  --color-deep-sky-blue-300: #7db7ff;
  --color-deep-sky-blue-400: #519dff;
  --color-deep-sky-blue-500: #2280ff;
  --color-deep-sky-blue-600: #206dd8;
  --color-deep-sky-blue-700: #1957ae;
  --color-deep-sky-blue-800: #074082;
  --color-deep-sky-blue-900: #052c5c;
  --color-deep-sky-blue-950: #00193f;
}

SCSS

$deep-sky-blue: #1e71e3;
$deep-sky-blue-rgb: 30, 113, 227;
$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);
}