A masked gunman killed 12 people and injured dozens more when he opened fire on crowds of people during a midnight showing of the new "Batman" film at the Century 16 theatre.
Suspect James Eagan Holmes, 24, has been taken into custody by police.
Reuters reports that 30 people remained in hospital on Friday evening, 11 in a critical condition.
The shooting has stunned the nation. A US flag was flying at half mast over the White House in Washington on Friday.
President Barack Obama called for prayer and reflection in the aftermath of the tragedy.
"While we will never know fully what causes somebody to take the life of another, we do know what makes life worth living," he said.
"The people lost in Aurora loved and they were loved. They were mothers and fathers, they were husbands and wives, sisters and brothers, sons and daughters, friends and neighbours.
"They had hopes for the future and they had dreams that were not yet fulfilled."
Members of the community in Aurora were planning to gather for a prayer vigil on Friday evening but decided to postpone it until 1800 MT on Sunday evening.
Colorado state representative Rhonda Fields announced the vigil on her website yesterday morning.
She said: "As a mother and survivor of a murder, I am horrified, shaken, and distressed over this enormous loss. It is time for us to collectively strategise to address preventative factors to ensure community safety and well-being. I will do everything possible to support the families, friends and community members whom have been impacted."
Explaining the decision to postpone the vigil, she said: "I think it's best to postpone tonight's prayer vigil until we have an official list and can properly honour them."
Denver First Church held a prayer vigil on Friday night joined by worship artists Moriah Peters and Rhett Walker "to help the community grieve and cope" following the shooting.
Denver Archbishop the Rev Samuel Aquila led a Mass last night at the Queen of Peace Parish for everyone affected.
Archbishop Aquila and Auxiliary Bishop James Conley said in a joint statement: "For those who were killed, our hope is the tender mercy of our God. We commend their souls, and their families and friends, to God's enduring love.
"For those who were wounded - physically, emotionally and spiritually - our hope is in their recovery and renewal. To them we offer our prayers, ours ears to listen, and our hearts to love."
Pastor Brady Boyd, senior pastor of New Life Church, tweeted: "Sad day in my state. Pray with me for the family and friends affected by this senseless and evil act."
Desperation Band tweeted: "Tragedies like this leave us speechless. Please pray with us for all affected by the shooting in Aurora last night."