Swedish's word order is often described as subject-verb-object (like english) but maybe a more accurate way to put is is "verb second". That means when you begin a sentence with things that aren't the subject (such as enligt honom), the verb takes the second "slot" in the sentence after the initial clause.
You can see this in a few other sentences too, such as...
-"Där är hon!" Literally "there is she!", because där is at the beginning. For regular word order you would say "Hon är där."
-"Idag äter jag." "Today eat I". In contrast to "Jag äter idag."
Usually swedish does this to emphasize a different part of the sentence, like saying I eat TODAY.
This page http://www.thelocal.se/blogs/theswedishteacher/2010/03/17/word-order-part-1/ talks about word order a little more in-depth.
Why not "Enligt honom är det skärpet grönt"? May be I am confused. I had an example before where definite article such as det or den should be used even if the object is in the definite form. I thought the same should be applied here as well!! Could you please explain? Thanks