Validation: How to make non required fields "valid" on submit...

Validation: How to make non required fields "valid" on submit...

I have some fields that require no validation and some that require it. The valid css I made in green color.

Now when I click on submit the validated fields show green and the non requested are left yellow that I use.

Is there a way to somehow on submit make all the fields to have valid class?

Sorry if I ask something obvious. I am a newbee in jquery...