Makikato, I'm not sure about that blue tint showing through. I know my reddish Pecan color is showing through but that is probably because under that Pecan color is actually snow white. Now that my hair is white in places I get my own natural highlites when it is dyed. Today is my fourth day and my hair is a rich reddish brown in the sunlight. I'm pleased with how the Prell Shampoo has lightened it but I'm going to switch to another brand so that it's not stripped out to fast.
Your blue tint may just fade as well. Try the Prell Shampoo for at least three days and you should be able to tell whether or not you need professional help.