Outside of T.Y. Hilton, the receiving corps is made up of names most people have never even heard of. Hilton is the only reliable target for Andrew Luck. Besides Hilton, the team has Ryan Grant, Dontrelle Inman, Zach Pascal, and Chester Rogers. Rogers is used as the primary punt return man as well as playing wide receiver.
One notable thing I saw during the bout with the Jaguars was the lack of communication between Luck and Inman. On what was supposed to be a short pass, Luck was forced out of the pocket and needed to toss one deep to Inman, who had beat the coverage and had an open lane to the end zone. When the ball was thrown, Inman was backpedaling, facing Luck and could not get turned around in time to go get the ball. Now, it is possible that Inman was not supposed to be targeted, as he was being used to open up a route underneath. However, I believe there should be communication between Luck and Inman in that situation.
There are a few wide receivers in the draft that could be drafted by the Colts. Guys like Marquise Brown of Oklahoma, A.J. Brown of Ole Miss, and Parris Campbell of Ohio State would be my favorite targets.