Gmail will now support CSS media queries

     Color
          causes the affected text to be displayed in a specified
          color. The "color" command requires a parameter that is
          specified by using the "param" command. The parameter
          data can be one of the following:

               red
               blue
               green
               yellow
               cyan
               magenta
               black
               white

          or an RGB color value in the form:

               ####,####,####

          where '#' is a hexadecimal digit '0' through '9', 'A'
          through 'F', or 'a' through 'f'. The three 4-digit
          hexadecimal values are the RGB values for red, green, and
          blue respectively, where each component is expressed as
          an unsigned value between 0 (0000) and 65535 (FFFF). The
          default color for the message is unspecified, though
          black is a common choice in many environments. When
          nested, the inner "color" command takes precedence.

Odd that it's 96bpp colour, of all things.

That said, we still need to get this sort of thing in Microsoft Outlook, and both that and Gmail really need to support CSS to something of a normal standard, like with say Apple Mail or what not. There's no real reason email standards should be different to browser ones, except with the former not having Javascript included.