Re: specifying colors outside srgb gamut with extended-linear-srgb

I don’t think any cartesian color model, and especially anything RGB-based is "intuitive". That's what polar color models are for (LCH, JzCzHz etc), which more closely match the way humans think about color.
IMO extended sRGB is primarily useful as a translation space, not for humans to specify directly, negative coordinates or not.

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Lea Verou
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> On Jun 8, 2021, at 08:32, Michael Smith <miksmith@attglobal.net> wrote:
> 
> Hi colorweb members.
> 
> Using extended-linear-srgb seems intuitive when colors are inside sRGB gamut, if I want a yellow that is twice as bright as a regular bright sRGB yellow, I use (r,g,b)=(2,2,0) instead of (r,g,b)=(1,1,0).
> 
> What if I want my application to use a nice saturated BT.2020 yellow instead, which is out-of-sRGB gamut, for example (r,g,b)=(2,2,0) in BT.2020 linear would translate to (r,g,b)=(2.145699727, 2.016698845, -0.237459323) in extended-linear-srgb with a negative blue value. Do we really expect users to specify negative color values?  I'm concerned that will be non-intuitive to users without a color science background.  Or maybe we intend users to only feel comfortable with extended-linear-srgb when colors are inside sRGB gamut?
> 
> Thanks,
> Mike
> 
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