Hi, a really quick question, I've a client who I normally do foils with bleach 6 percent, this is normally a creamy white colour in 30 mins or there abouts, however I need to apply another set of highlights to another client straight after my first and don't have anyone to wash off my first client, I'm worried that I'll leave the bleach on for too long.... If I use bleach and pastel will I still get the same result if left on for longer?? X