Well is it (a) dark grey(b) bright yellow(c) deep purple(d)rusty redand what is the forma to (FegO4) for exampleand yes I am a scientist
May just need new brake pads. Disconnect the battery for about 2 or 3 minutes, reconnect it and see if the light comes on right away. Whatever the cause, it needs to be addressed asap. your brakes are not something to put off. Consider buying a Chilton or Haynes repair manual for your car, you can find most answers in there with a little reading.
For a scientist, that's a pretty incoherent question.
i get old shavings from auto shops that turn rotors and drums dunno if that helped at all, but Good Luck
