So, I worked the color thing over with the new library version from Google and some additional testing. The colors should now be extracted quicker and the colors actually used will clash less often. As a tradeoff they will now be slightly more pastel-y. I also updated it so that the text and icons in the toolbar never become unreadable if the background color is too light by varying the text color aswell.
Here is a before - after example of a bookcover that had particularly garish results in earlier versions:
The update has been pushed to Google Play and should be available in the next few hours
