Re: sRGB color support in NS port [PATCH]

[Steve Purcell]

On 21 Dec 2013, at 16:16, Jan Djärv <address@hidden> wrote:

> Hello.
> 
> This has been done in another way in trunk.
> Customize ns-use-srgb-colorspace to use sRGB.  Default is to use calibrated 
> space.


I appreciate you taking the time to commit those changes.


> 
> Note that images still don't use sRGB color space.  Nor do they with the 
> patch below.


No, and of course that is correct.


> Also, this is not what the documentation says is the right way to display 
> colors on OSX.


That’s actually not at all clear to me from the docs: I haven’t found anything 
which says that programs may only accept from users hex colour literals in the 
calibrated RGB space.  The docs appear to simply say that that is the space to 
use within NS programs for shuffling R, G and B values around.  What we’re 
talking about here is how to interpret user colour input, and how to display 
colours back to the user as RGB triplets.

To be useful, the user-oriented RGB notation should presumably denote colours 
which will be displayed consistently on all machines. For that to be even be 
possible, those colours must be in an absolute and standard colour space.

On Windows, the RGB colour literals will be assumed to be coordinates within 
its default sRGB space. On OS X, emacs will claim that they are in the vague 
“calibrated” space, which is not sRGB, so they will automatically look 
different between the two platforms. This seems like a shortcoming to me, and 
it’s not clear to me that making the color space a user preference is the 
correct fix, at least if the default is the calibrated space.

But maybe I've missed something and/or my logical understanding of the 
situation is flawed, and I’d be happy to find out how. :-)

Cheers,

-Steve