You're asking an almost philosophical question, so bear with me for the response.
Color in the conventional sense is the part of the spectrum of light that is between 400-700 nanometers in length. Since the biggest atom around is more than 1000 times smaller than the shortest visible wavelength of light, no atoms have color in the conventional sense.
X-rays do interact with atoms just like regular light interacts with larger objects, and different wavelengths of x-rays interact with different sized atoms more, so just like different wavelengths of light between 400-700 nanometers in length interact differently with different materials and give rise to what we call color, x-rays between ~0.01-1 nanometers in length interact different with different atoms, and could be considered a "color," although it would be more metaphorical.
The reason many things you see have color is because they have delocalized electrons with energies at the range that can interact with visible light (if you've taken physics, E=h*nu, and c=gamma*nu, so the energy of something can be correlated to its wavelength). These typically consist of larger molecules, not individual atoms. Graphite, for example, has delocalized electrons and can therefore absorb light of every color (hence, it's black). Diamond has no delocalized electrons, and does not absorb light. The reason it "shines" is because parts of the actual diamond are roughly the size of visible light, so it can still interact with light.
In metals, the valence electrons are generally delocalized along the entire size of the object (which is why metals conduct electricity, which consists of moving electrons, so well). Silver is actually not very different from many other metals in color and appearance, it is just not very reactive, not very toxic, and easy to work with. Gold (and platinum) which have distinctive colors, are due to fairly complicated concepts. Essentially, since the nucleii of gold and platinum have so many protons, the attraction between the nucleii and the outer-electrons causes the electrons to accelarate to speeds that are close to the speed of light. When speeds get close to the speed of light all sorts of crazy phenomena start happening, which are called "relativistic" effects, after Einstein's theory of general relativity. Essentially, gold and platinum both have their distinctive colors because of the relativistic effects of their heavy nucleii.
This is a complicated topic, and the relativistic effects for example are not typically covered until a graduate-level course in inorganic chemistry. If you are thinking about these issues realize that you may have a brilliant and very-well paying career ahead of you as a chemist, physicist, or material-scientist. The interactions of light with materials are very important to everything from solar cells to displays like televisions, projectors, media (CDs/DVDs are read by laser beams), communications (fiber-optics transmit light instead of electricity), etc. I highly encourage you to take some more advanced classes and consider a career in these fields. Good luck.