For new users, you need to understand the different uses of the colored nozzles, as they can cause potential damages to the targeted surfaces and even hurt you if being used incorrectly. And in general, you’ll find your pressure washers come with 5 different color options, each representing a certain level of power and concentrated stream that comes out from your machine. Red - the first one is the red nozzle which features a 0° nozzle that sprays water directly into the targeted surfaces. And with the concentrated stream, it will offer the highest level of pressure power, which can be harmful if being sprayed directly on your body. Yellow - the yellow nozzle offers the 15o angled nozzle that is best used to break up dirt on concretes or wood surfaces. You can use it in the surface preparation stage before applying the detergent or cleaner. Green - this slightly toned-down nozzle comes with the 25o spray angle and a broader stream for cleaning up dirt and mud after the preparations stage.  White - for dedicated surfaces, the 40o nozzle will deliver a wide stream and decent spray power to help you clean up dirt without damaging the paints or coating. You’ll find it being used mostly in woods. Black - for applying detergent, the black nozzle with its broad and low-pressure stream will be more suitable for adding detergents or soaps.