anchor.diff:  <% function 'rgb($red $green $blue)',
               'rgb($red $green $blue / $alpha)',
               'rgb($red, $green, $blue, $alpha: 1)',
  +            'rgb($color, $alpha)',
               'rgba($red $green $blue)',
               'rgba($red $green $blue / $alpha)',
               'rgba($red, $green, $blue, $alpha: 1)',
  +            'rgba($color, $alpha)',
               returns: 'color' do %>
     <% impl_status dart: '1.15.0', libsass: false, ruby: false do %>
       LibSass and Ruby Sass only support the following signatures:
   
       * `rgb($red, $green, $blue)`
       * `rgba($red, $green, $blue, $alpha)`
  +    * `rgba($color, $alpha)`
   
       Note that for these implementations, the `$alpha` argument is *required* if
       the function name `rgba()` is used, and *forbidden* if the function name
  
positive.code:     @debug rgb(95%, 92.5%, 89.5%)  // #f2ece4
      @debug rgb(0 51 102 / 50%)  // rgba(0, 51, 102, 0.5)
      @debug rgba(95%, 92.5%, 89.5%, 0.2)  // rgba(242, 236, 228, 0.2)
    <% end %>
  <% end %>
  
  
negative.code:     as percentages.
    <% end %>
  
    If `$red`, `$green`, `$blue`, and optionally `$alpha` are passed, returns a
    color with the given red, green, blue, and alpha channels.
  
    Each channel can be specified as either a [unitless][] number between 0 and
    255 (inclusive), or a percentage between `0%` and `100%` (inclusive). The
  