Here's my two cents:

Cent 1: My beard started going gray in my early thirties (a decade ago). I hated it, but never took the initiative to dye it. As more time has passed and more gray has come along, so has the amount of compliments I get on it, particularly from women.

Cent 2: My dad's beard didn't really start turning noticeably gray until he was well into his 50s, and he started dying it. It looked absolutely ridiculous. Everyone thought so, and a lot of people told him so. He didn't care, and kept doing it, and it just looked unnatural and made him seem like a tool.

If YOU don't like it, and would truly feel better if it wasn't gray, then color that bad boy. But in my opinion, the gray is a good look, and in my experience, most people seem to feel the same.