Yes, colored marks can shed some light on the background of the dog and can increase likelihood of quality. But we are talking about likelihood, meaning chance, not a guarantee. 60% may be better than 10% but if you fall into the other 40%, tough.
Also, a dog is not checked for genetic diseases in order to attain a conformation title. It is up to the breeder's ethics to be conscientious about this. And champion does not always mean excellent quality (dogs who won by entering substandard dogs to get points from or become champions through switching), and excellent quality dog does not always mean good producer.
Quote:Green marks tell us that offspring from them are, at the very least, within the standards of conformity for the breed. Rest easy knowing that offspring from a green mark are more likely to not have hereditary diseases and physical abnormalities. And when you breed to/from green marks, you will most likely get a good litter, basing on conformity.
All green marks tell us is that a particular number of offsprings of that dog achieved titles. It doesn't mean all or even majority of her pups are good quality. A bitch can have dozens of substandard pups with only 3 nice pups and still get that green mark. Also, a bitch that produced well in the past will not necessarily produce the same quality when bred to another male, even if that male is a Sire of Merit.
What IS a pointless activity is counting the number of colored marks thinking that more is better. For what is the point of an increased likelihood if or when what you get in actuality still falls short? There are many dogs with numerous colored marks in their pedigree that are substandard and ill-bred/have genetic diseases. There are no shortcuts. A breeder must make a thorough study and assessment of the individual dog and his/her line.