'appelblauwzeegroen'? Never heard of it, in my 42 years of being a native speaker of Dutch. Not too many references on the web either, except for a hint that it might mean 'ugly, undefinable color' (so, not referential).
Even splitting it up, 'apple blue; sea green' does not make any sense to me. Well sea green, maybe a bit, but not really in combination with the rest. Since it's a composite word* you can't find it in a dictionary, so I can't really check whether it really exists.
* One word made out of multiple, like the English "car mechanic" would become "automonteur". Though automonteur is an example common enough to have its own entry: http://www.woorden.org/woord/automonteur
Edit: as per this comment[1], I've ran it past a Belgian guy: the word seems to be Flemish indeed. He knows it as "a color between green and blue".