Why do certain colors look different from a re-print?
There are many possible factors that can affect the color on your printed materials. The weather outside can play a part in affecting how the ink dries on the paper, and can change the color slightly. The ink density and constant on-press fluctuations in color, printing press running temperature or blanket wear, may also affect color slightly. It is impossible to expect any professional printer to produce exactly the same printed blue on two separate days.