are metals shiny because of the electron sea which surrounds the atomic lattice of the metal sample. are metals more shiny because the electron are more evenly distributed on the surface?
Your question concerning the scaffolding that makes up various metals, in relation to their appearance is a unique one. As far as I know, what determines the appearance of various metals is determined by the demarcation of the atoms that they are composed of.
Various material have a statistically higher chance of reflecting the photons of a wide range of the elements(as metals are conductors of electricity). That is why we use metal to make up our mirrors (certain metals have a high percent chance to reflect almost every element; e.g. aluminum.) This is due to the fact that most metals have electrons that exist a considerable distance away from the nucleus. This means that the electrons can be released right at the surface of the material, and in effect, light has a greater chance of being visibly reflected into your eye (electrons reflect light, and since these electrons are so close to the surface due to their distance from the nucleus, they have a smaller percent chance of becoming reabsorbed before you see them).
If you want an amazing book that explains the statistical mechanics of photon reflection by material, I recommend QED by Feynman. If someone else has more to say about the distinctive look of metals based on their atomic structures, I would love to hear about that. As far as I know though, it mostly has to do with the fact that various metals reflect various kinds of photons from different elements. As a result, the more elements a metal reflects, the shinier it appears.