I've heard it said that a designer should almost always use subtle, simplistic style in the design of a typical user interface. Is that really the case?
For example, Windows 8 is very bright / loud, and it seems to be popular, but that doesn't necessarily go beyond the current trends.
I'm looking for an example of subtlety being a valuable aspect in all GUI design, rather than just a feature of preference.
As it is, it seems that the balance between GUI subtlety and vibrancy can be ignore or upheld without any consequence beyond the world's current user preference.
What are some of the pros & cons of using subtle style for user-interface design vs those of using bright, loud styling?
Is there an inherent value in GUI color subtlety, or is it's value based purely on user preference?