My boyfriend has dirty blonde hair that he calls brown. But the front is obviously blonde. Comparing his dark blonde hair to yours, I think your hair is brown. It may look blonde in the light, but that's just light. I have dark hair that looks honey brown in the sunlight, even thought my hair is definitely not honey brown.
It can be both. Most hair dressers base their opinion on the brand of color they use which has a neutral level from 1 being the darkest and 10 being blonde. There are blondes that go higher but not normally natural. So depending on the brand they are using it could be either one. 4.bp.blogspot.com/.../haircolourchart.jpg