If it's something like wash your hair with lemon juice three times a week while chanting 'goldy locks goldy locks make mine shine' I would say yes but it's the lemon juice more than the magick.
I will say 'maybe' to small changes like your eyes are blue and you want people to see them as green, but this does not physically change your eye colour, it would be an illusion with energy.
Any glamour spell that simply asks for you to say a few words will never work. [Example, that scene from The Craft where the girl waves her hand in front of her face and poof her eye and hair colour change]
I see magick as a safety net of sorts. Yes, it can be used in many ways, but it's wiser to cast when you need something, not because you want something. If you want lighter hair, get some dye. [Its like seeing a spider and hitting it with a sledgehammer when you could of grabbed a tissue.]