Blue Coal load using powder dye from the Huber breaker.
Reading red coal load using red tint liquid from Sherwin Williams.
There were other colors, including silver, but I can't remember the coal company.
The dye was more then just marketing, it was also used to help control dust. In the case of Blue Coal, the dye was mixed with a liquid, possibly oil, and sprayed as the coal went down the chute to the hoppers. The inside of the breaker where the cars were filled was covered in blue.
