[racket-dev] Adding alpha to color%

Done.

At Wed, 24 Nov 2010 10:44:59 -0700, Matthew Flatt wrote:
> I would like to add alpha to `color%', but I haven't gotten around to it.
> 
> At Wed, 24 Nov 2010 17:28:33 +0000, Noel Welsh wrote:
> > Why was the alpha channel made a property of the dc, rather than (in
> > addition to) the color? For some use cases specifying alpha as part of
> > the colour is more convenient, and Cairo supports both IIRC. (That is,
> > you can specify alpha as part of a color or as part of the drawing
> > process.)
> > 
> > N.