Blue
In order to mix navy blue you use black and blue. There are different shades of navy blue, so you will have to determine how much of each color you need to use. Mix the black slowly into the blue until you get the shade of navy you want.
purple
a very dark shade of that color example blue+black=navy blue
blue or light blue, depends on how much of each you mix together
BLACK
If I am thinking of the same color, it is a mix between a really dark navy blue and a dark gray.
The colors you mix with sky blue to get navy blue would be a dark blue or a black. These will make a navy blue.
mix light blue and a bit of white then add a dark blue colour and mix it all in together
Blue the color of water and water bending
Navy blue comes from blue mixed with black.
navy-green-pea
mix red and blue