bug#8402: 24.0.50; Hex colors are not rendered correctly on OS X (Cocoa)

[Lars Ingebrigtsen]

Alan Third <alan@idiocy.org> writes:

>> >> For example, 'M-x set-face-background RET default RET #fdf6e3 RET'
>> >> results in a frame background color which, when sampled using Apple's
>> >> "Digital Color Meter" utility, has hex value #fff8e8.

[...]

>> When I try it with emacs 28 on macOS 11.6.5 I get the
>> background color 0xFCF6E5.  So it seems quite close.

Thanks for checking.

> I think all this is a result of macOS's heavy use of colourspaces,
> specifically conversion between "generic" and "SRGB" colourspaces.
>
> But to be perfectly frank, colour on macOS confuses me so much so I
> could be talking nonsense. If anyone does want to mess with this bear
> in mind that if you mess it up it results in HUGE performance
> penalties as every drawing action then has to run through colour
> conversion routines.

As Howard says, the colours are a lot closer now than when the bug
report was filed, so perhaps it's good enough now and we don't have to
change anything?  (For other systems, the colours we end up to are
pretty much defined by the system.)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no