Color code toolbar move buttons - so it's easier to distinguish them
Move to Spam/Trash/Archive need color coding, so we can distinguish them better. Ideally, when and how they appear should be customizable, but yeah...

We will work to continue to improve the design into the future.
-
Bukoko Ikoki commented
The titles of read mails and unread mails font and background colors are a bit confusing as well. The contrast is not exactly striking. Furthermore, some texts like the sender appear in bold mode which typically reminds an unread message.
-
Tom B commented
Generally, if you could make colour schemes simple enough (such as an editable CSS) so that folk could customize, that would be good for any of us who aren't afraid of a CSS file.