Yahoo Mail has been updated to 5.3, and brings a bunch of new features and changes with it. It is now much simpler overall, and allows you to pick from over 11 new themes for each added account.
The themes can be applied to all connected accounts including Yahoo Mail, Gmail, Outlook.com, Hotmail or AOL. Just head to Settings then Themes to change the color.
Also, some other new features are, ability to rename accounts, add subfolders, photo options to quickly save images, or move them to the text’s body or separate attachment, and the ability to “enable tappable stars to see them in your inbox and other message lists”. You can also set custom swipes to star any message you want as well.