======= Date Modified 24 Oct 2011 17:08:04 =======
As an arty type, I reckon it should all be composites of green - the colour of the sea: yellow for the things only penguins find interesting (because that was a good flavour of choccy biccy); blue for the polar bears (because they are cold) and green for the things they both like because that's blue and yellow combined - and, as I say, it also signifies the sea.
However, as your supervisor has requested differentiation by itallics I'd do that too, keeping the colour coding because her preference is only due to the, most probably misguided idea, that you won't be able to print colour.