It would be great to have an option to change the theme of the spotify app on iOS. The black color is stressing my eyes. Having an option to change the background color will be a great option. This might be the only reason why I would go back to iTunes. The background is very pleasant to my eyes.
Updated on 2018-02-24
A similar idea has also been suggested here:
Regardless of status, please vote for it, and add a comment there, so it may be considered. Any update on the matter should be posted there. :)