Small light brown imperfection on gum

[Onyxzxxx]

Hi I have a small light brown hole in my gum behind my molar as the gum starts to go to the top of the mouth, no tooth pain no noticed bleeding no gum pain either

 

[Dr M]

Does not sound like anything sinister. Might be some melanin pigmentation, an amalgam tattoo or just a different shade of gum tissue. Difficult to say without a better clinical picture.
The best would be to mention this to your dentist, the next time you go for a check-up and then they can have a look at it.