#417D8E

CSS

:root {
  --mysterious-blue: #417d8e;
  --mysterious-blue-rgb: 65 125 142;
  --mysterious-blue-oklch: oklch(0.556 0.068 218.5);
}

.element {
  color: var(--mysterious-blue);
  background-color: hsl(193 37% 41%);
  border-color: oklch(0.556 0.068 218.5);
}

Tailwind CSS v4

@theme {
  --color-mysterious-blue: #417d8e;
  --color-mysterious-blue-50: #e1faff;
  --color-mysterious-blue-100: #d0eef8;
  --color-mysterious-blue-200: #b5dce9;
  --color-mysterious-blue-300: #91c0d0;
  --color-mysterious-blue-400: #70a8b9;
  --color-mysterious-blue-500: #4e91a4;
  --color-mysterious-blue-600: #437b8b;
  --color-mysterious-blue-700: #35626f;
  --color-mysterious-blue-800: #254851;
  --color-mysterious-blue-900: #183239;
  --color-mysterious-blue-950: #091e23;
}

SCSS

$mysterious-blue: #417d8e;
$mysterious-blue-rgb: 65, 125, 142;
$mysterious-blue-light: mix(#fff, $mysterious-blue, 20%);
$mysterious-blue-dark: mix(#000, $mysterious-blue, 20%);

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