#999AA3

CSS

:root {
  --dark-ages: #999aa3;
  --dark-ages-rgb: 153 154 163;
  --dark-ages-oklch: oklch(0.688 0.013 281);
}

.element {
  color: var(--dark-ages);
  background-color: hsl(234 5% 62%);
  border-color: oklch(0.688 0.013 281);
}

Tailwind CSS v4

@theme {
  --color-dark-ages: #999aa3;
  --color-dark-ages-50: #f4f5f9;
  --color-dark-ages-100: #e7e7ec;
  --color-dark-ages-200: #d3d4da;
  --color-dark-ages-300: #b6b7be;
  --color-dark-ages-400: #9d9ea6;
  --color-dark-ages-500: #84858f;
  --color-dark-ages-600: #707179;
  --color-dark-ages-700: #595a61;
  --color-dark-ages-800: #414247;
  --color-dark-ages-900: #2d2d31;
  --color-dark-ages-950: #1a1a1d;
}

SCSS

$dark-ages: #999aa3;
$dark-ages-rgb: 153, 154, 163;
$dark-ages-light: mix(#fff, $dark-ages, 20%);
$dark-ages-dark: mix(#000, $dark-ages, 20%);

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