#4A7B9E

CSS

:root {
  --zenith: #4a7b9e;
  --zenith-rgb: 74 123 158;
  --zenith-oklch: oklch(0.563 0.076 241);
}

.element {
  color: var(--zenith);
  background-color: hsl(205 36% 45%);
  border-color: oklch(0.563 0.076 241);
}

Tailwind CSS v4

@theme {
  --color-zenith: #4a7b9e;
  --color-zenith-50: #e3f8ff;
  --color-zenith-100: #d3ecff;
  --color-zenith-200: #b9d9f3;
  --color-zenith-300: #96bddc;
  --color-zenith-400: #75a5c8;
  --color-zenith-500: #558db4;
  --color-zenith-600: #497798;
  --color-zenith-700: #3a5f7a;
  --color-zenith-800: #28465a;
  --color-zenith-900: #1b303f;
  --color-zenith-950: #0b1d28;
}

SCSS

$zenith: #4a7b9e;
$zenith-rgb: 74, 123, 158;
$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);
}