1. A method comprising: performing a first segmentation process on a digital image that searches for a first cell component type having a predetermined color, wherein the digital image depicts tissue that is stained with a test biomarker to have the predetermined color, and wherein the first segmentation process includes: identifying a starting pixel in the digital image; expanding from the starting pixel into each successive neighboring pixel so long as the neighboring pixel has a color that is not more dissimilar to the predetermined color than is the previous neighboring pixel; and halting the expanding into successive neighboring pixels at a boundary at which the neighboring pixel of each boundary pixel has a color that is more dissimilar to the predetermined color than is the boundary pixel; performing a second segmentation process on the digital image that searches for a second cell component type that has the predetermined color; identifying the test biomarker as a stain for the first cell component type if the first segmentation process identifies the first cell component type; identifying the test biomarker as a stain for the second cell component type if the second segmentation process identifies the second cell component type, wherein both, neither or only one of the first and second cell component types can be identified; and displaying on a graphical user interface whether the test biomarker is a stain for the first cell component type and whether the test biomarker is a stain for the second cell component type.