Subtle Blue

CSS

:root {
  --subtle-blue: #d9e4e5;
  --subtle-blue-rgb: 217 228 229;
  --subtle-blue-oklch: oklch(0.911 0.012 203.5);
}

.element {
  color: var(--subtle-blue);
  background-color: hsl(185 19% 87%);
  border-color: oklch(0.911 0.012 203.5);
}

Tailwind CSS v4

@theme {
  --color-subtle-blue: #d9e4e5;
  --color-subtle-blue-50: #f1f6f7;
  --color-subtle-blue-100: #e4e9ea;
  --color-subtle-blue-200: #cfd6d7;
  --color-subtle-blue-300: #b1b9ba;
  --color-subtle-blue-400: #97a1a1;
  --color-subtle-blue-500: #7e898a;
  --color-subtle-blue-600: #6a7474;
  --color-subtle-blue-700: #555c5d;
  --color-subtle-blue-800: #3e4444;
  --color-subtle-blue-900: #2b2f2f;
  --color-subtle-blue-950: #181b1c;
}

SCSS

$subtle-blue: #d9e4e5;
$subtle-blue-rgb: 217, 228, 229;
$subtle-blue-light: mix(#fff, $subtle-blue, 20%);
$subtle-blue-dark: mix(#000, $subtle-blue, 20%);

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