Question regarding colors in transition metals

[scorpio_tkh]

Hi how would I go about explaining the reason why copper and gold are colored whereas silver is not??

 

Strange thing is that Cu, Ag and Au are all part of the same group in the Periodic table.

 

Did some research on the Net and I came up with energy differences in the d-orbitals that resulted in color, however, that does not explain why Ag is not colored. Would anyone like to help me on this issue??

 

Thanks in advance.

 

regards

scorpio_tkh