A rabbi cannot base a ruling on digital pictures. Among other things, variations in light and in screen tint could alter a ruling.
However, before you go, you and your husband could sit down with your current rabbi for training in this area. You would not learn to answer questions, but how to identify which cloths present a real question and which do not.
Update June 2020: Whenever possible, stains should be evaluated in person and not via a photograph. However, in situations like yours, where a woman does not have access to a halachic authority, we recommend the Tahor App. This app (available on iPhone and some models of Android phones), uses special color calibration technology to ensure that the stain is photographed and transmitted accurately.