The smell is horrible [SEP] The smell is overwhelming, the worst I've ever encountered in a hair dye. I'd suggest keeping the windows open and use a fan.<br /><br />It's easy to use, pretty much the same instructions as any other hair dye I've tried. For best results, it's important to do the allergy and stand tests as instructed.  Also follow the instructions about not massaging It into the scalp. It burns a little if that happens.<br /><br />It covers grey well. It lightened dark blond hair somewhat, and produced an uneven time, which is part of the point, but which seemed a little erratic for my taste.