Created attachment 262874 [details] testcase Specifying the `color` property has no effect when specified with the :placeholder-shown pseudo-class. In the test case, the first input element should show the text in yellow. Instead the default light grey is rendered. Strangely (?) the WebKit inspector tells that the computed value is indeed yellow. The second input uses the prefixed pseudo-element, that works fine. Safari 9, OS X 10.11 and 10.10 Nightly on OS X10.10
I think this is not a bug. See: https://github.com/Fyrd/caniuse/issues/2150#issuecomment-165012958
Safari and Chrome behave the same, and indeed it seems like the WG believes this behavior is correct. Firefox works the way the author expected.