I don't know how accurate it is, but this site is interesting reading about tongue color and what it indicates:
http://www.womanknows.com/health-behavior/news/53/
I don't see it listed as a possible complication at the University Of Maryland Medical Centre website:
About 90% of gallstones cause no symptoms. There is a very small (2%) chance of developing pain during the first 10 years after gallstones form. After 10 years, the chance for developing symptoms declines. On average, symptoms take about 8 years to develop. The reason for the decline in symptoms after 10 years is not known, although some doctors suggest that "younger," smaller stones may be more likely to cause symptoms than larger, older ones. Acalculous gallbladder disease will often cause symptoms similar to those of gallbladder stones.
Biliary Pain or Colic
The mildest and most common symptom of gallbladder disease is intermittent pain called biliary colic, which occurs either in the mid- or the right portion of the upper abdomen. Symptoms may be fairly nonspecific. A typical attack has several features:
The primary symptom is typically a steady gripping or gnawing pain in the upper right abdomen near the rib cage, which can be severe and can radiate to the upper back. Some patients with biliary colic experience the pain behind the breast bone.
Nausea or vomiting may occur.
Changing position, taking over-the-counter pain relievers, and passing gas do not relieve the symptoms.
Biliary colic typically disappears after 1 to several hours. If it persists beyond this point, acute cholecystitis or more serious conditions may be present.
The episodes typically occur at the same time of day, but less frequently than once a week. Large or fatty meals can trigger the pain, but it usually occurs several hours after eating and often awakens the patient during the night.
The condition commonly returns, but attacks can be years apart.
Digestive complaints such as belching, feeling unusually full after meals, bloating, heartburn (burning feeling behind the breast bone), or regurgitation (acid back-up in the food pipe) are not likely to be caused by gallbladder disease. Conditions that may cause these symptoms include peptic ulcer, gastroesophageal reflux disease, or indigestion of unknown cause. [For more information, see In-Depth Report #19 Peptic ulcers and In-Depth Report #85 Gastroesophageal reflux disease.]
Symptoms of Gallbladder Inflammation (Acute Calculous and Acalculous Cholecystitis)
Between 1 and 3% of people with symptomatic gallstones develop inflammation in the gallbladder (acute cholecystitis), which occurs when stones or sludge block the duct. The symptoms are similar to those of biliary colic but are more persistent and severe.
They include the following:
Pain in the upper right abdomen that is severe and constant, and may last for days. Pain frequently increases when drawing a breath.
Pain may also radiate to the back or occur under the shoulder blades, behind the breast bone, or on the left side.
About a third of patients have fever and chills.
Nausea and vomiting may occur.
Anyone who experiences such symptoms should seek medical attention. Acute cholecystitis can progress to gangrene or perforation of the gallbladder if left untreated. Infection develops in about 20% of patients with acute cholecystitis, and increases the danger from this condition. People with diabetes are at particular risk for serious complications.
Symptoms of Chronic Cholecystitis or Dysfunctional Gallbladders
Chronic gallbladder disease (chronic cholecystitis) involves gallstones and mild inflammation. In such cases the gallbladder may become scarred and stiff. Symptoms of chronic gallbladder disease include the following:
Complaints of gas, nausea, and abdominal discomfort after meals; these are the most common symptoms, but they may be vague and difficult to distinguish from similar complaints in people who do not have gallbladder disease.
Chronic diarrhea (4 - 10 bowel movements every day for at least 3 months).
Symptoms of Stones in the Common Bile Duct (Choledocholithiasis)
Stones lodged in the common bile duct can cause symptoms that are similar to those produced by stones that lodge in the gallbladder, but they may also cause the following symptoms:
Choledocholithiasis
Jaundice (yellowish skin)
Dark urine, lighter stools, or both
Rapid heartbeat and abrupt blood pressure drop
Fever, chills, nausea and vomiting, and severe pain in the upper right abdomen. These symptoms suggest an infection in the bile duct (called cholangitis).
As in acute cholecystitis, patients who have these symptoms should seek medical help immediately. They may require emergency treatment.