anchor.diff:      @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 %>
  +
  +  ---
  +
  +  If `$color` and `$alpha` are passed, this returns `$color` with the given
  +  `$alpha` channel instead of its original alpha channel.
  +
  +  <% example(autogen_css: false) do %>
  +    @debug rgb(#f2ece4, 50%); // rgba(242, 236, 228, 0.5);
  +    @debug rgba(rgba(0, 51, 102, 0.5), 1); // #003366
  +    ===
  +    @debug rgb(#f2ece4, 50%)  // rgba(242, 236, 228, 0.5) 
  +    @debug rgba(rgba(0, 51, 102, 0.5), 1)  // #003366
     <% end %>
   <% end %>
   
  
positive.code:     as percentages.
    <% end %>
  
    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
  
negative.code: <% 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
  