A beautifully toned coin is a coin that has aged well. The magnificent aging of silver, in particular, is analogous to the magnificent aging of deciduous leaves every year, in the right climates, before they turn brown, the brilliant yellows and reds of the fall's foliage. This doesn't always happen with either leaves or silver. You need the right environment. When it does happen, it pleases the eye. Color is simply more appealing than gray.