Re: [css4-color] Grayscale shorthand (with alpha)

On Wed, Apr 18, 2012 at 1:14 PM, Brian Manthos <brianman@microsoft.com> wrote:
> Rudolph Gottesheim:
>> The use cases I was talking about are, as I said, mostly shadows. And most of the time
>> you don't want a color shift in your shadow. You just want to darken part of the background.
>
> Can you elaborate on what you mean by "color shift"?  I'm curious if you mean something like "just multiple each color channel by a fixed constant" or something else.

I think you're misreading Rudolph.  When he says "you don't want a
color shift", I believe he's talking about your reference to a "'black
and white' muted photo effect", which is actually changing the color
of something.  Rudolph isn't attempting to do anything like that (and
that would indeed be best as a filter).

His examples show what he's asking for:
* creating a partially-transparent dark shadow
* putting a partially-transparent "dark" or "light" background on some
text placed over a busy image, to aid in establishing proper contrast

Both of these are handled, within current CSS, with
partially-transparent colors on the "gray" axis.

~TJ