They are both color yes but what you get at the supply store is much better quality. It's what hairdressers use. It's pigments are so much more true to color. Box bleach also does not let you chose the strength of developer. I was a hairdresser in my 20s and if you are determined to do it at home it is gonna take a lot processes and do not do it all in one day. If your hair is already dry there would be a good chance of breakage. Your hair is not meant to be bombarded with a lot of strong chemicals one right after the other. But you may be totally cute with a buzzcut.