#4F799B

CSS

:root {
  --zenith: #4f799b;
  --zenith-rgb: 79 121 155;
  --zenith-oklch: oklch(0.559 0.071 243.9);
}

.element {
  color: var(--zenith);
  background-color: hsl(207 32% 46%);
  border-color: oklch(0.559 0.071 243.9);
}

Tailwind CSS v4

@theme {
  --color-zenith: #4f799b;
  --color-zenith-50: #e5f8ff;
  --color-zenith-100: #d5ebff;
  --color-zenith-200: #bcd8f1;
  --color-zenith-300: #9abcda;
  --color-zenith-400: #7ba4c6;
  --color-zenith-500: #5c8cb2;
  --color-zenith-600: #4f7696;
  --color-zenith-700: #3f5e79;
  --color-zenith-800: #2c4559;
  --color-zenith-900: #1d303e;
  --color-zenith-950: #0d1c27;
}

SCSS

$zenith: #4f799b;
$zenith-rgb: 79, 121, 155;
$zenith-light: mix(#fff, $zenith, 20%);
$zenith-dark: mix(#000, $zenith, 20%);

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