I prefer red over blue but I like blue as well. I think having black lines is what makes it look attractive. I love space blue too just to change it up with the colors. My only phone in (navy) blue was my Sanyo SCP-5500. It's a nice color too. Doesn't show fingerprints.
The Note7 looks decent enough too. If the iPhone has it in that option and the space gray has light colored antenna lines, then blue it is for me. Those renders of space black and space blue with the dark lines actually makes the 7 design more attractive than the 6 and 6s.