I want to use a wash-out hair dye (L'oreal Pulse) but I'm scared!?

I really want to use this dye because out of my 3 friends I'm the only one brave enough to try it and we all want too. I have light/medium brown hair with natural highlights. I have never used anything (chemical wise) besides hairspray in my hair. I heard it works differently with different hair types. My hair... show more I really want to use this dye because out of my 3 friends I'm the only one brave enough to try it and we all want too. I have light/medium brown hair with natural highlights. I have never used anything (chemical wise) besides hairspray in my hair. I heard it works differently with different hair types. My hair is really silky smooth and is not frizzy and is very straight (naturally). I really want to know if it will stay in more than 8-10 washes (I shower everyday so that would be like a week and a half) and if it will take out my natural highlights and I want to know if my hair will turn back to its normal color. I start high school the 28th of August and I definitly want my hair to be back to normal by then and preferably in the amount of time the package says! My friends and I just want to do this for fun to see what I would look like with blonde hair (we are doing the cool blonde color). So if anyone has any answers to any of those questions please answer! I'm scared to do this!
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