Aesthetics is something that always fall to individual tastes. Some wanted their app to simply follow the OS theme, others want it to look plain, yet others like me wants to make it a bit colorful or somewhat unique thinking it will spice up the app.
However, sometimes we tend to overdo the look. For example, in the past I tend to create a pageframe with several pages each having its own colors (theme should be set to .F. otherwise the color will be ignored). In the first glance, things look cool to my taste but then in the end either I simply turn the theme back on because I get tired of the multitude of colors or I just retain one color for all pages with theme still set to .F.