Re: [csswg-drafts] [css-color-4] no contrast guarantee on semi-transparent colors

> > Ignoring the context would mean to assume worst case.
>
> "Worst case" is fully transparent, which automatically fails, so we can't do that. 

By that I meant that in a situation like [white text on `rgba(0,0,0,0.5)`](https://leaverou.github.io/contrast-ratio/#white-on-rgba%280%2C0%2C0%2C.5%29), we would need to know the color *behind that* to caluclate the contrast. Unfortunately we do not know it. So in order to still guarantee sufficient contrast, we would have to check the worst possible case (in this case white text on `rgba(0,0,0,0.5)` on white, which is 4).

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Received on Thursday, 27 July 2017 12:10:09 UTC