Thalia Identity guidelines applied in Django backend

One-sentence description

Thalia Identity guidelines applied in Django backend

Why?

More 'huisstijl' more better

Current implementation

Thalia admin is ugly blue-ish.

Suggested implementation

This could be nice magenta #E62272 and black. Just a CSS thingy I think.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information