Can you combine orange and green?

Orange is a secondary colour made by mixing equal parts of the primary colours, red and yellow.

Green is a secondary colour made by mixing equal parts of the primary colours yellow and blue.

Any time you mix all three of the primary colours (red, blue and yellow) you get some form of grey or brown).

There is no way to remove a colour from a mixture, therefore it is not possible to mix anything with green that will result in orange.