You are right John, this level is far to be easy or even medium. Until now, I didn't find the solution. Considering the fact that the creator is still active on the site, I won't take the decision to change the category.
@nelson90: this might need to be switched to hard as this is not your normal patterned solve. I can get either 3 of the colored groups into their goals except for the 4th one. Definitely not easy.
Ok, I can always get either 3 of the 4 colored groups in their goals but that 1 group always remains, what method could be possible for this? I need a hint/picture please!!