Yes, Fanpop appears to have some logic in place to prevent identical content being posted all over the site, which includes links. This is also reflected in the fact that, when creating a club, you can only list the club in three different channels. While it is possible that a given link (or club, or video) could be appropriate to more than three clubs, it's much more likely that anything posted to more clubs would be spam. The site has a pretty bad problem with spam already, so I'm glad that there are such limitations, even though it can occasionally limit one.
If you want to cross-post about the different colors clubs in each color-related club, I recommend writing an article with all the links in ONE club, then posting to each club's forum with a comment containing the link to that article. The nice thing about having a forum thread in each color-related club for "useful links" (or whatever you'd like to call it) is that other users who might find/provide similar links in future have a clear place to put them so they're all in one place.
If you want to cross-post about the different colors clubs in each color-related club, I recommend writing an article with all the links in ONE club, then posting to each club's forum with a comment containing the link to that article. The nice thing about having a forum thread in each color-related club for "useful links" (or whatever you'd like to call it) is that other users who might find/provide similar links in future have a clear place to put them so they're all in one place.