#979797

CSS

:root {
  --million-grey: #979797;
  --million-grey-rgb: 151 151 151;
  --million-grey-oklch: oklch(0.676 0 0);
}

.element {
  color: var(--million-grey);
  background-color: hsl(0 0% 59%);
  border-color: oklch(0.676 0 0);
}

Tailwind CSS v4

@theme {
  --color-million-grey: #979797;
  --color-million-grey-50: #f5f5f5;
  --color-million-grey-100: #e8e8e8;
  --color-million-grey-200: #d4d4d4;
  --color-million-grey-300: #b7b7b7;
  --color-million-grey-400: #9e9e9e;
  --color-million-grey-500: #868686;
  --color-million-grey-600: #717171;
  --color-million-grey-700: #5b5b5b;
  --color-million-grey-800: #424242;
  --color-million-grey-900: #2e2e2e;
  --color-million-grey-950: #1b1b1b;
}

SCSS

$million-grey: #979797;
$million-grey-rgb: 151, 151, 151;
$million-grey-light: mix(#fff, $million-grey, 20%);
$million-grey-dark: mix(#000, $million-grey, 20%);

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