It is very important to clean your Airbrush very carefully. For that you should always use the color associated cleaner, because only this really cleans all the paint from the gun. External Companies or cheap cleaners don't work very well.
For cleaning, the cleaning liquid is (just like the color) poured into the airbrush - wait a few seconds - and spray strongly. To clean the color cap a cotton swab is very helpful. It should be soaked in cleaner. Then the airbrush is ready for a color change.
For a final cleaning the nozzle and the needle needs to be cleaned.