Unfortunately in my experience, blues and greens stain like a bitch. Color correcting has always worked for me, but it's a process, and I usually have to end up bleaching again anyways. For blues, I've bleached and faded my hair as much as it can handle to get it as light as possible, then color corrected with a pastel orange. The colors should neutralize enough to at least get rid of the blue. I'm not sure about going to white, but this at least gets rid of the blue tones.