Same username color in "People" Chats

### Description

It seems to me like the color of the username is always the same in every chat (Perhaps it's based on the username hash or something like that?). This is problematic in 1-1 Chats (People) if both have the same color or a similar color. It makes it a lot harder to identify at a first glance who has written what (especially if both also have the default profile picture, which will look rather similar then as well).

Different Solutions:
- (Automatically) Change the color of the other person for just me (client-side) -> Automatic approach would be preferrable
- Give People the sender and receiver always the same color in 1-1 chat (i.e. like in whatsapp or similar, where the sender is always green and the reciever is always blue) -> This also makes it easier to identify the sender and reciever in a screenshot for example
- Use additional visual distictions. For instance messages of the sender right aligned, of the reciever left aligned (similar as in basically every other messenger) -> That might be a good idea in general, at least optional