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Re: CSS Transparent Background and 1.4.3?


From: Patrick H. Lauke
Date: Jan 23, 2017 5:19PM

On 23/01/2017 18:28, Jim Homme wrote:
> Hi, According to what I just read, transparent is the default if a
> CSS background color isn't coded by the developer. Since I'm totally
> blind,, how does that affect testing for 1.4.3, contrast? For
> instance, are the results different for black text on a white
> background, specifically coded, than they are if the developer just
> specifies black text and allows the default to take over?

Assuming you mean a developer doesn't set explicit background color
anywhere, including the body/html elements:

- browsers used to default to a medium/light grey colour as the default;
however, most (all?) browsers these days default to a white default for
the body/html

- users *may* have specified that their browser should use specific
custom default colours. For this reason, not specifying at least an
explicit colour for the body/html elements in addition to a foreground
colour would lead to the explicitly defined foreground colour being
displayed over any kind of colour - making this impossible to test for
conclusively since it will depend on the user's settings (unless your
evaluation explicitly mentions that the result is only valid for default
browser values).

Patrick H. Lauke

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