Re: [csswg-drafts] [css-color-5] How should negative percentages behave in color-mix()? (#6047)

Looking at the spec, what is confusing is not the interpolation/extrapolation of negative numbers, it's the resolving two different percentages that are phrased as having to equal 100% but can be out of bounds both in the positive and negative direction.

If I specify one angle at 110%, and using what the spec says, and calculate the other percentage with `1 - p`, I end up with the second angle of -10%. Now I have 110% and -10%, what I do with that? This is where you start confusing the user. An algorithm to scale the values to 0 - 100 fails when you start mixing in negatives as you can have divide by zeros results that don't quite make sense. There may be a way to handle this, but it seems like it would be confusing to the user.

If there was a single percentage, and you knew which color it referred to, then you take out the complexity of resolving the two percentages (and the user thinking about how it resolves). You can feed in any percentage, negative or positive, and you can just send it straight through interpolation/extrapolation.

This is just my take at reading the spec and what I've been having difficulty wrapping my brain around.

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Received on Saturday, 6 March 2021 01:33:53 UTC