#E3E9ED

CSS

:root {
  --morning-mist: #e3e9ed;
  --morning-mist-rgb: 227 233 237;
  --morning-mist-oklch: oklch(0.931 0.008 236.6);
}

.element {
  color: var(--morning-mist);
  background-color: hsl(204 22% 91%);
  border-color: oklch(0.931 0.008 236.6);
}

Tailwind CSS v4

@theme {
  --color-morning-mist: #e3e9ed;
  --color-morning-mist-50: #f3f5f7;
  --color-morning-mist-100: #e5e8ea;
  --color-morning-mist-200: #d1d5d7;
  --color-morning-mist-300: #b4b8bb;
  --color-morning-mist-400: #9a9fa3;
  --color-morning-mist-500: #81878b;
  --color-morning-mist-600: #6d7276;
  --color-morning-mist-700: #575b5e;
  --color-morning-mist-800: #404345;
  --color-morning-mist-900: #2c2e30;
  --color-morning-mist-950: #191b1c;
}

SCSS

$morning-mist: #e3e9ed;
$morning-mist-rgb: 227, 233, 237;
$morning-mist-light: mix(#fff, $morning-mist, 20%);
$morning-mist-dark: mix(#000, $morning-mist, 20%);

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