You do not find it fun?
It can be remembered much more easily. I mean, it's not often that you see such a charismatic character with blue hair. And blue is fun, not as much fun as Yellow or Red from my pov but fun nonetheless, with the right Oda-like Pastel value, it's can be a pretty color
Now, the better question would be, why do you think Black is automatically the best color? Where does this come from?
Dude, how is 2018 going? Are you having fun there?