What is the compound(with it's color) which forms when dry chlorine and copper reacts together?

Copper and chlorine gas can form 2 compounds, CuCl and CuCl2. CuCl is produced industrially by directly reacting copper metal with chlorine gas at elevated temperature, producing a white solid.  CuCl2 can also be produced in a similar fashion, producing a blue-green solid.  Controlling the exact conditions of the reaction should cause one or the other to be formed, depending on which one is desired.