Re: [css-color] wider/deeper colors

Hello Florian,

Monday, February 15, 2016, 1:07:08 AM, you wrote:
> On Feb 12, 2016, at 11:16, Simon Fraser <smfr@me.com> wrote:
>> I think we’re prefer to avoid referencing external resources for
>> colors. What do you show before the resource is available? Transparent?


> That's a real issue, and we should find some way of dealing with
> the fall back, but I don't think we can have a solution that
> does not allow for external color profiles.

Absolutely. Otherwise we fail at one of the commonest use cases - CSS
for print publishing, where there is an external profile for the
target printing device but we want the same colors shown on screen.

> Otherwise we're not
> going to be able to do color matching with images, or to have print specific color profiles

Yes, color matching to wide-gamut images is the other really common
use case (and these are likely to be in AdobeRGB, or an even wider
space like ProPhoto)

> Maybe specifiying in the at-rule what kind of color model we're
> defining can give us an idea (even if approximate) of what to do
> when the resource hasn't loaded.


> @colors "name" {
>   profile: url() | from-image();

Extracting a color profile from the one embedded in an image is
interesting.

>   model: rgb | xyz | cmyk | ...;
> }

I think that is better done with fallbacks, like the ones in a font
stack. Given that we have some predefined names, they can be used last
in the same way that generic font-families are.

Also we don't need xyz (or lab) in that list; they don't need a
profile, they are already fully defined.

> Or maybe we can extend the color function to have an explicit fallback.


> Or maybe we can define that the color function defaults to
> currentColor,

Do you mean the existing CSS4 color function, or the function that
used to be called icc-color?

> or do that in most contexts but default to the
> background color in other contexts.


> Or maybe all of the above.

That does sound a little complex but I agree that currentColor is
going to be a better fallback than transparent black or whatever.


-- 
Best regards,
 Chris  Lilley
 Technical Director, W3C Interaction Domain

Received on Tuesday, 16 February 2016 09:35:12 UTC