Since bleach won't remove the stains, it is going to be difficult to get them out. You can try soaking the shirt in a white vinegar and water solution. Wash the shirt normally after soaking it for a day.
If the vinegar does not work, try making a paste of baking soda and water. Work the baking soda into the fabric with a utility brush. Let the shirt set for a couple of hours then wash it. This may remove the blue stains.
You can try making a paste out of Oxy-Clean powder and apply it in the same manner as described above. The Oxy-Clean is an oxygen based bleach that may remove the stains.
Don't mix the cleaning agents. Try one at a time.
If these don't work, then you will likely need to replace the shirt.