Hi Dear, Welcome to HCM. Understanding your concern. Thanks for your query . There are many reasons for discoloration of palate like :- - Due to some medicines like blood pressure lowering medicines . - Certain diseases like addison s diseases and heavy metal pigmentation. - Due to smoking . But in your case the pigmentation is due to excesses beta carotene in your body because of crangrape juice . These beta carotene sometimes increase toxicity in body . The pigmentation will go by its own as the level of beta carotene start decreasing from the body . So i would suggest you to consult your doctor about it . Also consult dentist to rule out other causes like allergic reaction to any dental appliance like amalgam tatto or dental infection. Hope your concern has been resolved. Best Wishes, Dr. Harry Maheshwari