Indy actually had a fantastic draft. Phillip Dorsett is insurance in case T.Y. Hilton decides to go elsewhere, in case Andre Johnson doesn't work out. D'Joun Smith was arguably the most talented cornerback pound-for-pound in this draft. Henry Anderson gives them a 3-4 end who can absolutely wreak havoc in the right system (in this case, Indy's system). Josh Robinson is a good running back and a steal for a sixth round pick. That's four good picks out of eight.
As for their undrafted free agents, they got four defensive players who should have easily been drafted: Al-Hajj Shabazz, Donald Celiscar, Zach Hodges, and Junior Sylvestre. They've fixed their secondary (Smith, Celiscar, Shabazz), helped out their defensive line (Anderson), got two very good linebackers (Hodges, Sylvestre), and got arguably the best deep threat in the draft, along with a running back who is a bigger Zac Stacy.
The Colts did well. They're well on their way to a likely Super Bowl appearance, if the Cheatriots don't interfere again.