'Gray' is the color of my birth but the ringing 'Bell' stole away my thunder. Sherlock's accomplice were my first words. what am I?

To solve this riddle, let's break it down into parts and analyze it.

First, the riddle states that "Gray" is the color of your birth. This suggests that the answer may have something to do with the color gray or a concept related to it.

Next, the riddle mentions a "ringing bell" stealing away your thunder. This could indicate a connection to the concept of thunder or lightning.

Finally, the riddle suggests that Sherlock's accomplice were your first words. This hints at a character or term associated with Sherlock Holmes.

Putting these clues together, the answer to the riddle is "Moriarty."

Explanation:
- The color gray represents Moriarty's last name, as it sounds similar to the word "mori" (which means "gray" in Japanese).
- The ringing bell refers to the phrase "Moriarty stole my thunder," which implies that Moriarty overshadowed the speaker or took credit for something significant.
- Sherlock Holmes is well-known for his arch-nemesis, Professor James Moriarty. By mentioning Sherlock's accomplice, the riddle suggests a connection to Moriarty.

So, the answer to the riddle "Gray is the color of my birth, but the ringing Bell stole away my thunder. Sherlock's accomplice were my first words" is "Moriarty."