You could try pristella tetras. Clear fish with cute yellow tipped fins. I also like Harlequin Rasboras. They're brown and black, sure, but they apparently school pretty well and look pretty snazzy as a group.
The dying neons could be that they were just from weak stock. Neons apparently have problems with their genetic availability, or something or the other. My first few groups of neons always had to have some individuals replaced, probably because of this.