I haven't had a lot of luck with Color Fiend at all. Special Effects or even RAW is okay if you get their dark blue
And I totally agree with wendybeth... Leave the bleach on for awhile. My dark brown takes about 1.5-2 hours to get to a good white. Wrap it up and reapply bleach ever 45 mins over where you already have the bleach to make sure it keeps working. I wouldn't leave the bleach on longer than 2 hours, most people quit out a lot earlier than that. You can always bleach again so if you want to play it safe do about 1.25-1.5 hours, then wash with cold water. Always wash the blue hair with cold water if you can because hot will pull the color out more quickly.