The Laboratory of Horse Reality is found on the right side of the city map. At this place you can check the testable color genes of your horses.
When accessing the laboratory, you can select which horse you'd like to get tested. Alternatively, when looking at the profile of your horse, the "Colors & Patterns" box on the Genetics tab features an orange button at the top. This button will take you straight to the laboratory and pre-select the horse for testing.
With a horse selected at the laboratory, the "Colors & Patterns" box will be visible underneath it. Tick the checkboxes for the genes you'd like to test. Premium members have a "select all" option to tick all checkboxes at once. Previously tested genes of this horse will have a green tick instead of a checkbox. Once ready, scroll to the bottom and click the orange "Perform tests" button. It costs 15 HRC per selected gene. As soon as the tests are complete, you get redirected to your horse's profile where you can view the results.
Each gene can be tested only once. This will permanently reveal its alleles - two letters which replace the initial question marks on the left side of the "Colors & Patterns" box. A notable exception is the KIT locus: Since several color genes are found here, the final allele code won't be visible until all KIT genes have been tested. If you only test for a specific KIT gene, its alleles only show up to the left if the test is positive.
The laboratory tests can only be performed on scientifically identified color genes. These are the genes listed in the "Colors & Patterns" box. There are untestable genes such as flaxen, sooty, and rabicano. They are known to affect horse color and can be identified by looks and pedigrees, but no laboratory tests exist for them yet.
Once the companies are finished, you can start your own laboratory as a scientist if you have completed the university course "Molecular Sciences". The company system is currently being re-worked, more information will be provided once it is known what exactly this company type will involve.