That adaption did go over two issues so that might have something to do with that. I'm recalling this from a thread I made back in February, so I'm hazy on the exact details of the manga, maybe I can dig up more information about it.
For reference here is the thread in question:
http://warioforums.com/index.php?threads/a-few-glimpses-of-wario-characters-in-mario-mangas.707/
And both of those are seperate mangas? Now that's interesting since it means the cyan design must've been commonly regarded as canon. As in, not only the piece of promo art of WL2, but also both of these manga artists use it, so it must've been a more widespread thing in Japan at that point, at least.