White Balance and Custom ColoursYou can't go wrong using Auto White Balance (AWB) most of the time, however, using appropriate white balance presets can improve colour accuracy. Considering weather conditions of Western European winter, the most suitable would be Cloudy. It can also be used under sunlight to make pictures warmer.
It is subjective, but I think that default colours of the G10 are too dull, and default sharpening is too high. Combined with automatic noise reduction it makes small details and sharp edges look coarse and introduces sharpening halos, which are ugly and difficult to get rid of. Here are 100% crops taken at default sharpening:
To fix this I created the Custom Colour setting with sharpening set to -2 and saturation to +2. Here is an example:
Colour modes also can be selected by pressing FUNC button. You may experiment with different mode (black & white, sepia, etc.) but after that I recommend switching back to the Custom Colour.