[whatwg] [html5] Rendering of interactive content

[Aryeh Gregor]

On Tue, Feb 10, 2009 at 10:30 PM, Ian Hickson <ian at hixie.ch> wrote:
>> If the UA suddenly displays hyperlinks in green and I decided that my
>> background is green, the user will complain with me, not with the UA (and
>> will probably switch to a different website)
>
> Authors should never the background colour without setting the foreground
> colour. So that would be the author's fault.

I don't think that's relevant.  If I, as an author, use the rule

body { color: white; background: green; }

and the UA uses the rule

:link { color: green; }

then links would be invisible despite my background color.  Although
authors are encouraged to always set colors and backgrounds together,
UAs conventionally do *not* do this for links, for fairly good reason.

You could say that not only should authors never set the background
color without setting the foreground color, they should also never set
the background color without setting the *link* color.  But this still
doesn't help if the UA (or a user stylesheet) uses

span { color: green; }

for some strange reason (not much stranger than green links by
default!), in which case everything is still messed up.

I don't think there's any way around this.  If a UA sets unexpected
style rules, it *will* break some sites.  I imagine that the response
to this is that while this may be so, it's possible that in some cases
it will be a tradeoff against platform integration or something, and
so it should still be up to the implementers to decide whether it's a
good tradeoff in their case.  The expectation would be that for
conventional browsers, it won't be.  This is pretty much just the
definition of "should" in RFC2119.