Hello Dear Thanks for your query, I will be most happy if I could help you out. First of all I highly appreciate you that you visit the dentist every 6 months for regular check-up. In your query if You would have mentioned the color of the saliva then it will be more helpful to me. There are several factors which can affect the color of saliva ranging from mild to moderate factors.For example • Use of tobacco in any form (most common cause). • GERD- Acid reflux, in which digestive juices from the stomach regurgitate into the esophagus, and in some cases in to the mouth also. • Thick mucus present in the the saliva may also cause such disoloration of saliva. • Eating or drinking colored food in the night can also cause the same. • Use of chlorhexidine mouthwash may also cause staining of teeth tongue and other intraoral surface. If someone with same symptoms arrives in my clinic, I would advice few things to him • Drink more of water. • To quit the habit of tobacco if taking tobacco. • To brush teeth and tongue twice daily. • To stop the use of chlorhexidine mouthwash for few days in the night. Hope this will help you. In case there is any more query or question regarding this in your mind, you are free to ask any time. Thank You and Take Care Regards