Some antonyms of "subtle" are...
Select one:
beautiful, attractive
understated, quiet
stupid, oblivious
loud, obvious

Loud,obvious

Explanation:

to be subtle,you need to make something that's out of place seem normal or ordinary, unseen and looked past by anyone around.Undercover alamost.

False

Explanation:

When you want to get your point your across, you want to be assertive. You want to people to know that you're  no push over. You want to make sure your point stands and make sure its sticks. You need to do all of this without being a bully, without being mean.  

I hope this makes sense :)