I've not been painting a whole lot recently but an art forum I belong to posted a challenge on painting whites.
Most non-artists think painting white is easy. Most artists know how difficult it really is! White contains a myriad of color in varying intensities and it is very, very difficult to get the right balance. In painting, everything needs to be simplified also so an artist can't really show all the colors they see in a white object or it would look uber strange to the uninitiated.
Anyway, I tried and don't think I did too badly considering these were done in a very short time period and in my not so favorite medium of watercolor.
Both paintings are about 5X7'' on watercolor paper