60% complete is pushing it mate
Looking on the webcam, all that you can see in the above photos is what is built, plus the splash-run. None of the stuff in between the first hill and the last two bunnyhills is built. Not to mention that no vertical construction has been done on the helix before the splash-run.
And, the thing you thought maybe track colour changes, is definitely your other suspision and is infact the case, it's the shadow of the very square/straight edged grey building behind the photo.
Looking good though! gonna have to try even harder to convince the missus to go with me to Ohio now!