dirt brown.
Both blue and yellow are primary colors. When mixed, they produce secondary color, green; shade depends on how much blue/yellow.
To get green you mix blue and yellow.
blue and green
you get the color blue
Blue and yellow
Blue is a primary color and that means that you can't mix anything with it to get royal blue. Yellow is another primary color, so mixing anything with yellow won't give you blue. Get the blue that you have and mix a very little black with it to get the royal blue that you want.
No color will mix with green to get blue. Blue is a primary color when mixed with another primary color, yellow, produces green.
Green
green
Green
Green
GREEN.