What are my fillings made of?

HI, r/dentistry! I've just had a few cavities filled. NOw, I'm uninsured, so I went to a local community health center to have it done. I'm not sure what exactly they used, and google is being unhelpful. My fillings are a matte color, bluish white or bluish-gray, they don't seem to be metallic, and they don't match my tooth color. With apologies for my inability to provide a picture, does anyone have a clue what's in my teeth?