Bootstrap 4.1.3 table-dark color different from default 'dark' but virtually identical

Created by: Scrabble96

The default definition of 'gray-dark' and 'dark' is #343a40 and this color is used several times for various selectors.

The table-dark and table-head th borders use color #32383e - defined as "color: $table-dark-color;" in the _tables.scss - which to the naked eye is virtually identical as #343a40.

So, I suggest that the color used for "color: $table-dark-color;" is changed to #343a40.

Sorry, I have looked for the theme-colors map but can't find it anywhere to edit it so I can't submit a pull request.