What kind of shampoo did you use???? I don't think I would use that on my hair....unless you want to bleach it out! If the shirt is bleached out, probably nothing will help to restore it.
you might want to treat the stain as either an acidic or alkali stain, depending on the shampoo ingredients. You may also check this site under perspiration stains, since the treatment could be similar to removing those sorts of acidic perspiration bleached yellow stains.
Login using the form on the top of the page to post feedback (if you are a registered user). If you have not yet registered, click here to do so. It's FREE!.