My hair dye didn't turn out right?

I just used 'N Rage's Purple Plum hair color and left it in for an hour and ten minutes, then washed the excess dye out. I dried my hair w/ a blow dryer and it's really dark and it's really hard to see the purple. I have naturally black hair and bleached it. It's still slightly wet but it's still really hard to see. Did I do something wrong or do I need to wait?