#3FA3DF

CSS

:root {
  --high-blue: #3fa3df;
  --high-blue-rgb: 63 163 223;
  --high-blue-oklch: oklch(0.683 0.127 239.1);
}

.element {
  color: var(--high-blue);
  background-color: hsl(203 71% 56%);
  border-color: oklch(0.683 0.127 239.1);
}

Tailwind CSS v4

@theme {
  --color-high-blue: #3fa3df;
  --color-high-blue-50: #d6fbff;
  --color-high-blue-100: #c3eeff;
  --color-high-blue-200: #a3dcff;
  --color-high-blue-300: #79c0f3;
  --color-high-blue-400: #4ca8e1;
  --color-high-blue-500: #008fd0;
  --color-high-blue-600: #0d79b0;
  --color-high-blue-700: #0c618d;
  --color-high-blue-800: #014869;
  --color-high-blue-900: #023249;
  --color-high-blue-950: #001d30;
}

SCSS

$high-blue: #3fa3df;
$high-blue-rgb: 63, 163, 223;
$high-blue-light: mix(#fff, $high-blue, 20%);
$high-blue-dark: mix(#000, $high-blue, 20%);

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