Photoshop: Create a way to find/select areas of minimum CMYK values for min dot printing purposes.

When searching for areas of less than 2% or 5% in any of the CMYK values, I use the eyedropper in areas that loo concerning. I would love a way (or maybe there already is...?) to flag the areas in an image that contain minimal CMYK values and possibly even select those areas to allow them to be filled.