A freshly dissected scale of a skinbow zebrafish. Epithelial cells covering the exposed portion of the scale are multicolor labeled. The cells have been labeled with a new fluorescent imaging tool called skinbow. It color codes cells by getting them to express genes encoding red, green, and blue fluorescent proteins at levels that are randomly determined. The different ratios of these colorful proteins mix to give each cell a distinctive hue when imaged under a microscope.
Source: Chen et al., (2016). Multicolor cell barcoding technology for long-term surveillance of epithelial regeneration in zebrafish. Developmental Cell 36 (6), 668-680.