Warning when processing.

[theozaurus]

When used in the Rails asset pipeline these warnings are emitted:

       WARNING on line 3, column 52 of /tmp/app/vendor/bundle/ruby/2.3.0/gems/rails-assets-barebones-sass-1.7.6/app/assets/stylesheets/barebones-sass/dist/helpers/_inc/_background.scss:
       You probably don't mean to use the color value `black' in interpolation here.
       It may end up represented as #000000, which will likely produce invalid CSS.
       Always quote color names when using them as strings (for example, "black").
       If you really want to use the color value here, use `"" + $colour'.
       WARNING on line 34, column 46 of /tmp/app/vendor/bundle/ruby/2.3.0/gems/rails-assets-barebones-sass-1.7.6/app/assets/stylesheets/barebones-sass/dist/helpers/_inc/_typography.scss:
       You probably don't mean to use the color value `black' in interpolation here.
       It may end up represented as #000000, which will likely produce invalid CSS.
       Always quote color names when using them as strings (for example, "black").
       If you really want to use the color value here, use `"" + $colour'.