Organic juices are made with certified organic flavorings. In order to be considered organic and bear the USDA seal, 95% or more of the ingredients used in certified organic flavorings have to be from organic sources. The lines they are processed on are not cleaned using chemicals or industrial solvents like most regular flavoring, or food companies would. They also do not contain any genetically modified organisms, and do not contain any chemical food additives.
Natural flavors are derived from the ingredients they represent. Cherry comes from cherries.
Artificial comes from a laboratory. They can be the exact same chemical make-up as the natural flavorings, just created in a lab.
100% VG juice is made with vg based nicotine, vg or alcohol based flavorings, and plain vg. (Typically)
There are no color differences between the vg juices, nor are the flavorings any better or worse than the other. (Except for individual preference) Some like the quality of the organics, some like how it's a 'greener' alternative.
Hope this answers your questions!