Hi all, It is my understanding that the color of a material results from the inability (or lesser ability) to absorb in that particular wavelength. Reading Atkins' "Physical Chemistry" (8th ed.), I run into a statement I couldn't quite get. On page 730 (chap. 20), he states the following: So far it makes perfect sense. But then comes trouble: If copper has fewer unoccupied energy levels that can be excited with violet, blue and green light, wouldn't that make it absorb less light of those colors and therefore exhibit a blue-ish color? And as far as I know (and as unambiguously stated in the end of the above quote), copper is red-ish. Any light on this would be most appreciated. Thanks in advance.