The former's work is coloful--they are titled "landscapes," but could easily be called "colorscapes" and if the artist said the images were from space or under a a tropical sea you would likewise take no issue with the description. If you check the Chambers Fine Art website (linked above) you will find that the artist works with more subdued tones with similar effect.
Zhao Zhao's paintings at Expo Chicago are all titled "Sky." These are below. When you check out Zhao's work on the gallery website you will find varied styles--from the sky paintings to sculptures in limestone to varied paintings with different color schemes and subject. If you put some of these pieces next to the work shown here you would never guess they were from the same artist.