Dying hair, fading, risk?

Ok so I had my dyed light blonde with bleach highlights about 2 months ago. It got really dingy and yellow with roots so I decided I wanted something diffrent. Dyed it a medium brown but it came out dark red. Used a corrective color over it so now its like a dark burgundy brown. I regret doing it at all. I shouldve just had the blonde redone. But Im gonna leave it thiscolor too prevent messing up my hair. How long does it take to fade so it doesnt look so dark and reddish burgundy. And will it mess up my hair if i bleach it in a month and a half so its blonde again for my graduation. keep in mind i have short hair.