Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that you are suffering from a condition known as
Black Hairy Tongue in which there is black discolouration of tongue caused due to accumulation of debris and food particles over the papillae over tongue and also there can be overgrowth of bacteria and yeast..
Also there can be staining caused by dyes present in foods and candy in your case..
Dehydration can cause dryness in mouth and it can cause more debris accumulation due to lack of
flushing action that is done by saliva..
It does not seems to be due to interaction of candies with the medication you are taking so no need to worry about it..
I would suggest you start cleaning your tongue with a tongue scraper..
Gargle with 1:1 solution of
hydrogen peroxide and water..
You can dip a soft toothbrush in above solution and gently brush your tongue..
Drink plenty of water..
Take more of chewy hard foods like carrots as they clean the tongue by frictional action..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.