I seem to have misunderstood. I thought Alain was asking for a monochrome variant to be designed for people who want to use that (e.g. if it's easier to print monochrome on a computer card than color), but looking more closely, I can see that he just wanted to see what the proposed logo looked like when you took the color away.
I don't think what I suggested would have any problem; just make the "continents" dark green and make the "ocean" light blue, possibly with black outlines to define the separation better.