Blue and white to get the desired shade. The more white you add the lighter shade of blue you will get. If you want a bit of violet, add a dash / drop of red.
You can mix blue and yellow to make green.
Since blue is a primary color there are no two colors to mix to create blue so you would just have to use a darker color blue and white.
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.
Yellow and Blue.
red and blue
yellow and blue.
blue
Blue and Red
Red, blue and green make yellow
Blue and red mix to make purple. Mixing these two colors together creates a new color, which is purple.
You cannot mix any color with blue to get red. Blue and red are primary colors.
Red and blue make purple.