In [4.6 CSSColorValue objects](https://drafts.css-houdini.org/css-typed-om/#colorvalue-objects), the method `CSSGray toGray();` should be removed, because [CSSWG resolved to drop the CSS Color 4 `gray()` function](https://github.com/w3c/csswg-drafts/issues/4621#issuecomment-572183475)
In 4.6 CSSColorValue objects, the method
CSSGray toGray();should be removed, because CSSWG resolved to drop the CSS Color 4gray()function