I think Jill is looking for the opposite--she wants neutral prints, "not brown and white." Are you using a chromogenic film processed in C-41 color chemistry by a conventional minilab on color paper? Brown tones are a common problem with this approach, but you can tell the lab you want the blacks to be black and the greys to be grey, and they should be able to adjust, if they know what they are doing.(posted 8618 days ago)Alternately, try a more conventional black and white film like Kodak T-Max 100 or Ilford FP-4 or Kodak Plus-X, take it to a professional lab, and have them print it on conventional black and white paper.
It is ultimately the paper (and some aspects of processing like the developer and toner used) that determines the tone of the image, not the film, but chromogenic films are designed for printing on color paper.