From the IDW forum under Global fan-forums Oct Hasbro Q&A:

Sometimes test shots come in and all of the molds are not cast in the correct colors. But that's why test shots exist, so that we can catch those problems before the toy is produced. In this example, an image of a Cyclonus testshot was released and fans had issues. But rest assured, the mold is going to remain purple and match the initial prototype image.
woot!!