On that page, I saw no photo of the emulsion itself, or a plate, but basically an emulsion is an emulsion. A bromoiodide emulsion is a yellowish red, with the intensity varying with grain size and iodide content. A chloride emulsion is white, and a bromide is slightly yellowish.

Spectrally sensitized emulsions take on the opposite color of the region to which they are sensitive, thus a red sensitive emulsion is cyan, and an ortho sensitive emusion (blue and green) is red. A pan sensitive emulsion is gray.

There are spectra of these in Mees and James.

PE