What does an amber/white warning light signify?

Question

I was driving today and i saw a lightbar on a truck that had an amber and white color combination. I thought white or clear was reserved for EMS. this is in iowa by the way

Answer 1

Either city or state road worker..

Answer 2

I don't think it "means" anything. I think it's just trying not to get hit!

Answer 3

road side workers, like construction workers.  that it?