The mix of colours for creating olive green -- whether in paints, dyes or for cake icing -- depends on the exact shade desired. With a bit of careful blending you can combine several colours to achieve that perfect olive green finish.
Olive green varies from a medium yellowish green, similar to the colour of green olives, to a dark, brownish green, to the greyish olive drab associated with military-issue clothing.
A standard olive or olive green -- a muddy, medium green -- can be made by combining yellow oxide or primary yellow with primary blue or green, and a small amount of black or white. Yellow acts as the base colour. The proportion of colours used varies with the shade of olive green.
Adding a small amount of red oxide or primary red will produce a browner shade. Yellow oxide and black, or yellow oxide, white and black create a greyer olive drab.
Olive green-coloured icing -- sometimes called khaki -- is made by mixing primary yellow, black and primary blue or green tint paste with a white icing base.
Adding orange, brown or purple shades to the mix of colours is likely to produce a grey, murky shade that doesn't resemble any olive green tint.