Copper(I) iodide is a white solid. It does not dissolve in water. It easily turns tan or brown. It is a reducing agent. The iodide easily oxidizes to iodine. Copper does not form a stable copper(II) iodide; copper(II) iodide breaks down right away to make copper(I) iodide and iodine. It dissolves in concentrated iodides like potassium iodide. When it is diluted, it makes copper(I) iodide again.
It can be made by reacting iodine and copper in concentrated hydroiodic acid. Another way would be to react copper(II) sulfate and potassium iodide. This makes copper(II) iodide which as said before breaks down right away to make iodine and copper(I) iodide.