The red hints aren't really a thing anymore. The passwords are either a word that has alot of emphasis or is repeated alot. If dave gives you hints at the vault then pay attention to those as they point to where the password can be found.
The first password is found in the bad end.
The next needs multiple passwords. Each are found in the bad endings. Using one will lead to a new chain of events on day 8 and the next password will be in the new chain of events.
There is something on Hoss's route on day 7 that helps with day 8 and allows to avoid one of the passwords. Think it happens on Orlando's route too but once you know the right password it will work on every route, day 8 is a universal one.