#5A9EE9

CSS

:root {
  --blue-bay: #5a9ee9;
  --blue-bay-rgb: 90 158 233;
  --blue-bay-oklch: oklch(0.687 0.131 252.3);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(211 76% 63%);
  border-color: oklch(0.687 0.131 252.3);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #5a9ee9;
  --color-blue-bay-50: #dcf8ff;
  --color-blue-bay-100: #cbebff;
  --color-blue-bay-200: #aed8ff;
  --color-blue-bay-300: #88bbfa;
  --color-blue-bay-400: #62a2ea;
  --color-blue-bay-500: #3c89da;
  --color-blue-bay-600: #3474b8;
  --color-blue-bay-700: #295d94;
  --color-blue-bay-800: #19446e;
  --color-blue-bay-900: #102f4d;
  --color-blue-bay-950: #031b33;
}

SCSS

$blue-bay: #5a9ee9;
$blue-bay-rgb: 90, 158, 233;
$blue-bay-light: mix(#fff, $blue-bay, 20%);
$blue-bay-dark: mix(#000, $blue-bay, 20%);

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