Scientists from Duke University genetically engineered a zebrafish to better understand how skin cells regenerate. The researchers programmed each individual cell to glow with a slightly different hue, creating the multicolored fish you can see in the video above. In effect, the researchers tagged the cells with their own unique barcode, enabling them to track how each cell behaves when it heals from an injury. They say this method of live imaging multicolored cells within a tissue can be applied to other tissues and species as well.