Yes, I use blue background color and I see why it might not look that good with it. However, I still prefer transparent background that changes based on user background color. Also one idea - what about white circle around MobileSheets icon? See attached image, it's tile of FeedLab and it looks great even with blue background..
EDIT: I've noticed FeedLab changes also it's "inside" colour and only white parts remains the same.
EDIT: I've noticed FeedLab changes also it's "inside" colour and only white parts remains the same.
Tablet: Surface Pro 8,
Other: Strich BT-FP2, USB-MIDI connection to Kurzweil Forte 7