The green cover is the official North American cover. The cover features the gate of time from Skyward Sword, which was a specifically chosen design for various reasons.
If you order the book through an American retailer you should be getting the green cover and Target may have just provided the wrong cover art on the site. But you should call to be sure if you're worried about getting the wrong copy.
For one it would be entirely in Japanese and I am relatively sure you're interested in actually READING the book
Secondly the green cover IS much nicer..
So I can't imagine that Target is selling the Japanese print book but if you're really concerned it would be worth calling in to find out.