This bug was discussed at the 2016-06-06 blocker review meeting [1] and determined to be an AccptedFreezeException as fixing this now will alleviate trying to fix it with an update in the future. The fix for this should be easy and anything broken will be easy to spot.

[1] https://meetbot.fedoraproject.org/fedora-blocker-review/2016-06-06/f24-blocker-review.2016-06-06-16.00.txt

According to https://developer.gnome.org/gtk3/stable/GtkInfoBar.html,

"GtkInfoBar has a single CSS node with name infobar. The node may get one of the style classes .info, .warning, .error or .question, depending on the message type."

and thus anaconda would apply a style to a particular message-type using something like:

.warning {
   background-color: a color;
   color: another color;
}

5affbbe5455f3805e3805e407719e793dad83b90 breaks this by overriding color with a .warning:backdrop selector.

(In reply to David Shea from comment #2)
> According to https://developer.gnome.org/gtk3/stable/GtkInfoBar.html,
> 
> "GtkInfoBar has a single CSS node with name infobar. The node may get one of
> the style classes .info, .warning, .error or .question, depending on the
> message type."
> 
> and thus anaconda would apply a style to a particular message-type using
> something like:
> 
> .warning {
>    background-color: a color;
>    color: another color;
> }
> 
> 5affbbe5455f3805e3805e407719e793dad83b90 breaks this by overriding color
> with a .warning:backdrop selector.

First, the documentation does not say what you seem to be reading into it. Widget states still apply and selectors including states have higher specificity than those without. 

Second, why would the backdrop state be present ? The anaconda window is focused and active, is it not ?

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