The eternal problem of the apostrophe...

I have started reading a self-published book that has a really good, intriguing storyline. It would be the perfect read if it weren’t for those pesky apostrophes. Can somebody explain to me why I have to read the sentence: “...the rich locks of hair, reflecting reds and gold’s pretty as the leaves in fall.” Why on earth did the author get the first plural spot on and turn the second one into a genitive singular? Why? Where is the sense in that? Is it sloppiness? That should never happen if the author wants to be taken seriously.