Wow, I didn't think #YouTube encoding would change the quality so much. My phone's MP4 is bottom, YouTube top. Same resolution, but their highest quality encoding still changes the color a lot.
In a year or two, the #YouTube#music app as an experiment will be considered a #fail and will be shut down. YouTube will then bring good music player controls (video queuing, skip next etc) to their video app. Till then we suffer.