It is now state personnel policy that, for the purposes of visibility, hair can be counted as visibility headwear so long as it is the correct color of bright orange.
I dyed my hair traffic cone orange one summer and asked if I still had to wear my hat. My boss was amused and asked his boss. His boss was also amused and asked his boss. On and on and on until a memo was issued signed by the director of the entire agency saying that no, anyone with traffic cone orange hair did not have to wear a hat.
I honestly don't know if I have any pictures from back then. I should, but I dunno where they would be.
At the time I was also fond of wearing brightly colored collared shirts too, so between my hair and my clothes I probably was safe to go hunting in terms of visibility.