Salmon eggs are red.
Every other fresh water fish I’ve dressed have had yellow eggs. So why is caviar black?
Because sturgeon roe is black? (Or very dark brown.)
(Am I missing something?)
Er… salmon eggs are caviar, at least in the proper sense (красная икра, red caviar, in Russian). Caviar from sturgeon ranges from black to light grey, depending on how much you want to pay for it.