Print off the spectrum. Clean the salt plates with acetone. Do NOT use water on the salt plates. In the transition metal complexes, many of these transitions occur in the visible region of the spectrum. However, once a spectrum is known, it is indicative of that particular compound.
Many transition elements do have characteristic colors in solution.
Once you obtain your spectrum, be sure to discuss the relationship between the color of the solution and the absorbance maxima in the spectrum. Print the spectrum. Be sure to turn off the lamp when finished. Do not use organic solvents to clean the plastic cuvettes. Rinse with distilled water and let air dry.