[css-color-5] in <space> syntax for linear-gradient() et al

[surma]

The nice thing about color-mix() is that it allows you to specify colors in a different color space then the color space in which the interpolation happens. As far as I can tell, linear-gradient() et al will always interpolate in RGB space, and I can’t find any changes to linear-gradient in CSS Color 4 or 5. Would it be feasible to add a in <space> syntax to linear-gradient(), similar to what color-mix() supports?

Here’s what gradients from blue to green would look like (I used JavaScript to generate these gradients using color-mix()):

cc @argyleink

[svgeesus]

Yes, there should totally be an in colorspace keyword added to gradients, to override the current sRGB default for legacy colors.

I think this is already discussed in Consider allowing gradients to include a color space for interpolation to take place in and also Don't force non-legacy colors to interpolate in a gamma-encoded space and Question: in what color space will gradient interpolation occur?

But that change would happen in CSS Images 4, not in Color 4 or 5.

[surma]

Ah good to know. If it’s already decided, then I’m happy to let this be closed.

[svgeesus]

Sadly there is a lag between "already decided" and "already in the spec" and you should not be required to be psychic or have attended every call for the last 5 years.

So I'm going to re-tag it to Images 4, and leave it open until done.