Actually, these tours are going to completely different places. Green tour goes to more further areas (225km in total in one day) which is quite impossible to do on your own and visit the greener part of the region. You visit Derinkuyu Underground City (the only problem is that as all the tour companies are doing exactly the same thing, there are crowds mostly in this place.) and Ihlara Valley (the greenest valley with a stream in Cappadocia) in this trip.
Red Tour goes to closer areas to Goreme such as Goreme Open Air Museum, Love Valley, Pasabag and more. You can easily walk to Goreme Open Air Museum on your own, but if you are a person interested in the history background of the place, you should visit the place with a tour guide. You can also take a taxi to all these places, but again the information part will be missing.
As people are having less time in Cappadocia than before, we did a special tour that blends this 2 tours. It is called as Highlights of Cappadocia tour and goes to many places in Red tour and takes the underground city and Pigeon Valley from the green tour. That way, you will visit the most important places in Cappadocia in one day and the next day will be on your own to go for a hike, horse-back ride, quad-bike tour or simply enjoy the pool in your hotel.