The ui of the tracking app needs an overhaul.

Change the color theme

We need a simpler color theme. The hole app shall be white/black and the toolbar at the bottom shall be lightgray/darkgray

Change the time tracking view

Instead of selecting the project in the select field the user shall be able to swipe left/right to schange the project. The play-button then get's the color of the project. If the user swipes to the an, the play button switches to an add button where the user can add a new project.