Filing in RHBZ is this is to do with Evo 3.12.3 on GTK+ 3.13.3, which is a slightly unusual configuration probably most commonly found in Rawhide. So, yeah, in current Rawhide, with evolution-3.12.3-3.fc21.x86_64 and gtk3-3.13.3-2.fc21.x86_64 , there's still a theming/color issue remaining in Evolution: when composing a message (either a new message or a reply), the pane that contains the new message text has a black background. I know someone is aware of this issue at some level, but wanted to make sure there was a bug report to track progress and make sure the fix makes it down to Rawhide.
Created attachment 914589 [details] screenshot illustrating the issue
Thanks for a bug report. This is for gtkhtml3, which was fixed only recently and will reach rawhide the next week, when the release will be done. It as reported as [1] upstream. [1] https://bugzilla.gnome.org/show_bug.cgi?id=732499
Confirmed working when I woke up today, thanks.