Gene knockouts in diploid organisms typically require molecular genotyping to distinguish wild-type, hemizygous, and homozygous individuals. We propose disrupting alleles by inserting two visually separable markers, enabling genotyping directly on the organismal level. We extend this strategy to four markers to allow systematic generation and unambiguous identification of specimens that are homozygous for both the insertional knockout and for a fluorescent reporter transgene, enabling phenotype characterization by fluorescence live imaging.