I thing there is a regoinal difference regards colours and is something I have noticed in Asia. I agree that in the West there is a growing propensity for saturated colours but in Asia the colours can become downright gaudy - not just saturated by bright and garish. I think it a a book by Michael Freemen that gave the intersting supposition that in the West we have been through the whole evolution of art as a representative medium, from merely a way of recording what happened with any sense of scale being secondary and perspective non-existent through to the painting-as-reality (for example the accurate representation of perspective or the analysis of colour by Turner). This has also pervaded our approach to photography. But in Asia art took a very different path and the accurate use of colour was far less important, so when they want to emphasise colour in a photo they see nothing wrong with whacking up all sorts of controls and it can look downright weird.
Not just in Asia. And, even there, India is quite different from southern China (both generally bold and colourful), which is very different again from northern China and Korea (more subdued), with southeast Asia displaying many influences from both southern China and India.
In the west, you can see a distinct difference between predominantly Catholic areas and predominantly Protestant areas. Paintings in Catholic areas - much of the western Mediterranean basin, including Italy and Spain - have tended to be bright, colourful and vivid, at least over the last 500 years. This seems to have also spread and influenced works and preferences in Latin America, the Philippines and other areas (pre-Spanish/pre-Catholic Filipino paintings are quite different from post-Spanish works). You may look at some of the 400-year-old works now and think they look a bit dull, but work backwards and take away 400 years of pigment fade, though air pollution and UV light, and you find that most of these works were, in fact, originally very colourful and strongly saturated - including many details and colourful ornamentations which have actually faded away completely over time. Conversely, works from Protestant-dominated areas have tended to be darker, with more muted tones. Compare and contrast the ceiling of the Sistine Chapel in Rome with St Paul's Cathedral in London. The former is bright and colourful, whereas the latter is much more muted, dark and subdued. Of course, there are many shades in between the two broad groups. Romanticist works, for example, tend towards darker shades, but use a lot of rich, saturated colours and a rendering designed to convey emotion (e.g. motion-blurred clouds or stormy seas) rather than the what-the-eye-sees approach of the realists and neoclassicists. Of course, this may also represent a north-south divide rather than one based on philosophical differences, although philosophical outlook certainly played a role. Northern areas, with long, dark winter nights, tended towards dark and muted tones, whereas brighter and sunnier southern areas tended towards bright and saturated tones.
