It seems like setting the background color is a work around, but I need to do more testing.
The issue is it only happens if the program is launched after its been unused for a long time like overnight so its not something that is quick to test. You need to launch the program outside of Xcode and then close it. Then let it sit all day or overnight and the relaunch it to see the issue. The screen with the charts is not the first screen the program displays. The issue is only when the program comes from the backgound. If its a fresh start by iOS it works fine. The bad backgound does not get fixed by new data being loaded in the charts or redrawing the chart, but if I go to a diffrent screen and then come back it resets to the proper backgound colors.
I went from 2.2.0 to 2.5.3 and then to 2.5.5. I never tried 2.5.2. I have only tested this on iOS7 with Xcode 5.0.1. The 2.2.0 version never had this problem with iOS6 or iOS7.
[ShinobiChartgetInfo] is reporting: ShinobiChart Version Version: 2.5.5, Edition: Standard