A while back like 1 year ago, i noticed my gum nearest to my tooth was changing color. what do i do?

Need a dental eval.: You need to be examined by a dentist to evaluate the condition of your gums and treat the reasons for the color change.

Inflammation?: If it is redder in color (plus swollen, bleeding?) it is most like gingivitis or gum inflammation. We can't diagnose it over the internet, so see a dentist for a definitive diagnosis and appropriate treatment.