SCSS gray scale

I made an adaptation in my project’s bootstrap.scss file to define all the gray variations by modifying only the gray color variable, maybe it can be useful for a friend.

// scss-docs-start gray-color-variables
$white:    #fff !default;
$gray:    #808080 !default;

$gray-100: tint-color($gray, 90%) !default;//#f8f9fa !default;
$gray-200: tint-color($gray, 80%) !default;//#e9ecef !default;
$gray-300: tint-color($gray, 70%) !default;//#dee2e6 !default;
$gray-400: tint-color($gray, 60%) !default;//#ced4da !default;
$gray-500: tint-color($gray, 50%) !default;//#adb5bd !default;
$gray-600: tint-color($gray, 40%) !default;//#6c757d !default;
$gray-700: tint-color($gray, 30%) !default;//#495057 !default;
$gray-800: tint-color($gray, 20%) !default;//#343a40 !default;
$gray-900: tint-color($gray, 10%) !default;//#212529 !default;
$black:    #000 !default;
// scss-docs-end gray-color-variables