The only way to make black by colour mixing is by combining the primary hues. To accomplish this with two colours, one can use one of three combinations: yellow and purple, orange and blue, or green and red.
Creating black by combining colours rarely results in an acceptable shade of black. Results can vary depending on the colour and type of pigment used. It would be necessary to blend colours by trial and error, adding more or fewer pigments until a desirable colour is achieved.