How do the dots under peoples names In the forums work? I saw they increased the amount under but like, I saw someone with 4000 posts and not full dots then someone with like 2000 and it was full and different colors, how do you fill them? How do u get color?

How do the dots under peoples names In the forums work? I saw they increased the amount under but like, I saw someone with 4000 posts and not full dots then someone with like 2000 and it was full and different colors, how do you fill them? How do u get color?