riddle - Short, but not sweet

Smoking makes me blush

And smell rather strongly
I'll achieve my purpose
If you answer this wrongly

Who am I?

Answer

You are a

herring

Smoking makes me blush

Smoking herring turns it red.

And smell rather strongly

Smoked herring has a strong smell.

I'll achieve my purpose if you answer this wrongly

A red herring is a clue meant to be misleading.

Short, but not sweet

A herring is a small fish, and it does not taste sweet!