On the signing of 27-year-old Hughes, manager Nigel Worthington told the clubs official website: "Andy is a player that myself and the coaching staff have admired for a long while," he told First News.
"We've had to be patient to get him, but that patience has paid off.
"Andy will add experience to the squad, is a very, very good player and will be a valuable asset. I am delighted to get him."
And on signing Colin from PSV Eindhoven, Worthington said: "I am delighted to get such a young player with experience and 12 years of education at PSV - a club with a great tradition of producing talented young players."For the fee that we are paying he is an absolute bargain for Norwich City Football Club and one with great potential."