Rename/change colour of email account

Hi. I haven’t been able to figure out how to change the email account name, after adding it in the Mail App. Rename, for example, “xxxxxxxxx @ posteo . net” to “Posteo,” or “Personal,” or whatever.

I also don’t know if it’s possible to change the colour of the accounts (that dot before the account name), like in the Calendar app.

Anyone knows if this is possible and how to do it? And if it’s not, is it in the app’s roadmap?

Thank you.