The Trinidad and Tobago international signs from MLS side Toronto FC after deciding to return to Scotland for personal reasons.
"He was keen to return, so I spoke with Mo Johnston at Toronto and moved quickly to bring Collin over here."
The 26-year-old first shot to prominence for Falkirk after scoring a hat-trick against Hearts in the 2003 Scottish Cup. After attracting the interest of Everton, he joined Dundee United where he spent four seasons with mixed success. The pacy forward then joined Toronto FC and, despite featuring in every game, was keen to return home to Scotland.
"I had six weeks to look at Colin and I think he is a more complete player than he was earlier in his career," said McInnes.
"He knows me, he knows a lot of the players from his time training here, and he knows the First Division.
"I think that will make him a great acquisition and he is still at the age where he can kick on and play at the level I think he can reach."