Decline to identify ethnicity?

I am currently applying to a job that requires a clearance and was just wondering if its bad to decline to identify ethnicity. I know its an equal opportunity employer but at the end of the day, the human element to it will always impact the opportunity. Thoughts?

The SF85/86 only asks for height, weight, hair color, and eye color.

I always decline. It had no impact upon my clearance or job offer.