The Magpies slipped to their fourth defeat on the spin as they lost 1-0 to Stoke City at the Britannia Stadium, with Erik Pieters scoring the only goal of the game in the 42nd minute.
"We are very disappointed because we came into this from three games where we did not play well, and then today we didn't play well again," Coloccini told the club's official website.
"It may have been a better scoreline but it was not a better performance than Southampton and Manchester United.
"They were lucky with the goal they scored but we lost again and it is not good enough. We have to improve and do that quickly before the end of the season."
Newcastle are ninth in the Premier League following the defeat.