It might be hard to get those colors that you have out if you are trying to go blonde. Unless you are covering that up mostly with a darker color, if you try and bleach thru those they are going to pull those same colors for awhile, and will need to be toned to get the right shade of blonde, and even then might not be the platinum color your going for. I think the color combo you want sounds very pretty though. Would love to see pics if you get it done. =)