Should I Train Caught but Uncertain Spam as Spam Before Deleting?

I am in the habit of scanning my AppleMail Spambox for messages that are caught as spam but not shaded grey, (that is the blue, orange, yellow shaded spams indicating less certainty) selecting them, then executing "Train as Spam” from the Message menu before deleting, thinking I am improving my ruleset and corpus.

Does this have any useful effect?

Thanks,
Steve

It’s better to only train the mistakes.

Also, Blue is actually more certain than Gray.

Thanks for the quick and thorough reply and for aiming me at the right doc sections. Got it !