Honestly, I think unless your teeth are severely stained, i don't think a slightly yellow glaze to your teeth is a big deal, I don't assume the person is unhygenic. I mean I floss twice daily, brush at least twice, and get professional cleaning done every three months so I never have vivibsl tartar or plaque. But I drink tea all day long as well, usually green tea, so I think being off-white is inevitable.