I am sure if you want to change the logo you have an expert already in mind. However, I can give an opinion on the App Logo appearance. If you see Appstore or Playstore apps generally, 3 colours are dominating the entire design back and forth. Blue, White and Red. Among all those apps a different colour will definitely stand out. Look at the Idea app/Spotify/Evernote apps for eg. This is my suggestion, but it would be better if you can just look at your app tray & decide on a stand out mix of colour from your installed apps itself.