A deeper "blue" toning is usually a good indicator, but not foolproof. If you are planting in a dry cactus mix, there is not much risk of the cut developing a rot condition, and roots will form equally well in dry soil or on a shelf. I personally believe maybe better in warm soil as the temp of the dirt does not fluctuate as rapidly.
I am also a fan of the dry powder "root tone", which is a rooting hormone. It stimulates root production, and inhibits rot.
At the end of the day, until you test run a cactus, you do not know its potency unless as Myc said, the cutting comes from a cactus that has been already proven to be of good potency.
I think you are over analysing this coleman.........................
If the scars feel hard and solid, dust them with rooting hormone if you have it, or not if you don't, and plant them just deep enough to hold still, about 1" or at max, 2 inches deep. Use a good loose cactus mix dry. You can support with a few chopsticks if you need to help them stay upright. If the dirt is kept warm, you should have some roots showing within a month, or sometimes a bit longer.
I will carefully lift my cuttings to verify roots. Once I see some, I replant at the same depth and tamp down the dirt more securely and then give them a nice drink. These cactus are actually pretty hardy and want to grow.
Just let them do that................................