Fabrics can have a variety of colors, textures, patterns, values, tones, etc., and etc. This only a portion of the pile of fabrics I’m “shopping through” for the Gyspy Wife Quilt which currently is a messy work-in-progress (WIP).
Converting to a black and white picture can help determine the value of a specific fabric — e.g. light, medium, and dark — which is often important in making up a quilt block. However, I don’t often use this tool as it takes too much time. Instead, I use red and green filters called value finders (or viewers).