Collingwood was named captain by the England and Wales Cricket Board (ECB) after Michael Vaughan quit on Monday, and was given a 14-man squad to face West Indies in June and July.
Collingwood, whose men host India in August and September, told a news conference shown on Sky Sports News he wanted more fight from England, who had a fairly dismal World Cup.
"We've played our best one-day cricket when we've been aggressive, taken the attack to the opposition, been positive when we go out to bat and had plenty of self-belief," he said.
"One thing's for sure, I'll be allowing the players to go out there and express themselves. That's when you play your best cricket.
As for the captaincy, he said: "It's a great opportunity to take our game to the next level and try to be successful in one-day cricket - to get the consistency in our performances but get the intensity going as well."
Vaughan, who is initially stepping down from international one-dayers to allow Collingwood to establish his captaincy, is not in the squad and neither is former skipper Andrew Strauss.
Andrew Flintoff, Sajid Mahmood, Marcus Trescothick and Ravi Bopara are all unavailable, while two uncapped players join the squad in Warwickshire batsman Jonathan Trott and Hampshire all-rounder Dimitri Mascarenhas.
There is also room for five players with limited one-day experience with England - Alastair Cook, Matt Prior, Owais Shah, Ryan Sidebottom and Michael Yardy.
Asked about the absentees, ECB chairman of selectors David Graveney said: "(Vaughan) put his hand up and said I should have played better, we should have played better at the World Cup.
"He said 'I don't deserve to be selected in light of how we played at the World Cup.' He's going back to Yorkshire -- (but) he'll be knocking on the door again.
"And I think Andrew Strauss will be doing the same."
Squad: Paul Collingwood (capt), James Anderson, Ian Bell, Stuart Broad, Alastair Cook, Dimitri Mascarenhas, Monty Panesar, Kevin Pietersen, Liam Plunkett, Matt Prior (wk), Owais Shah, Ryan Sidebottom, Jonathan Trott and Michael Yardy.