Revamp default theme

[travisnwade]

The default theme is a bit, how do we say, not super fantastic as a starting point for an emotion tracking app. I initially built it with a cyberpunk theme in mind, but think it should very likely be something more generic and fitting.

Something like calming backgrounds, soothing / warm color palette, etc to make this less ZOMG NEON EVERYWHERE!!!

Just a thought though.