A really, really dark blue or you could call black with a blue hue.
black and blue and silver
To make the color black with paint, you can mix equal parts of primary colors blue, red, and yellow. This combination will create a dark shade that appears black.
A darker navy blue
you don't
It is not possible to make the color brown turn black. Brown is a combination of red, green, and blue hues, while black is the absence of color. Mixing more black paint into brown paint will only darken the shade of brown, not turn it black.
If you are trying to make black paint with blue paint just add an earthy colour (brown) :)
Floquil and Scalecoat make the G.N. green. The Big Sky Blue paint scheme was blue, black, and white, so I'm not sure what color you are asking about.
Blue + black.
To make a dark blue color by mixing two colors, combine equal parts of blue and black paint. Mix thoroughly until you achieve the desired shade of dark blue.
mix brown and blue paint
Blue & Green make turquoise
Use black paint on its own, otherwise you will need to keep adding black until the grey becomes black enough. Adding a very dark blue to grey will make a black, but it won't be a proper black, more like a bluey black.