What colors do you mix to become navy blue?

It will take some patience and time, but to do this properly with primary colors, mix equal parts of yellow and red to get a true orange. From this mixture, very carefully mix in 3/4 parts of blue. This will come close, but very carefully add a touch more blue in tiny increments until you get the tone of navy you want.

All primaries mixed in equal portions makes black, not gray. This is why you use less blue. Purple and blue make a deep violet.

- Harold Sink - Artist

Blue is a primary color ... add some purple to it