Colantuono saw his side bounce back from defeat to Cagliari on the opening day with a win over Torino on Sunday.
Atalanta face Napoli next and, while Colantuono is aware of the challenge that Rafael Benitez's side will pose, he believes that defending champions Juventus are favourites for the Scudetto.
"They (Napoli) have a great squad – probably one of the strongest in the league," he told Sky Sport Italia.
"In my opinion, though, Juventus are probably just slightly ahead of everyone else.
"It's going to be tight this season, however – more so than recent years."
In terms of his own side, the former Torino coach wants to ensure Serie A football next season before targeting anything else.
"Our goal is to save ourselves as soon as possible," he continued.
"But we have many complicated matches before that, starting next week against Napoli."
Napoli won the same fixture last season 3-2, thanks to an 81st-minute Goran Pandev goal.
