Gnome shell extension that makes background in overview darker so even white text is readable on bright or colorful wallpapers.
Before:
After:
This extension supports gnome-shell versions from 3.14 to 3.24 (and most probably would work on many other versions as well).
https://extensions.gnome.org/extension/1177/darker-overview/
git clone git://github.com/mkoura/gnome-shell-darker-overview.git
cd gnome-shell-darker-overview
cp -r darker-overview@mkoura.github.com ~/.local/share/gnome-shell/extensions
Restart the shell and then enable the extension.