While you don't "need" to have a high white calico in order to possibly produce high white babies, I'm sure it doesn't help your odds to be purposefully breeding a low white calico in the hopes of magically getting a bunch of high whites.

Me personally, I would not breed low white calicos like the ones pictured above. I want to represent the morph to the best of my ability. Selective breeding plays a key role in ball python morphs and I think pairings using low white calicos with the hopes of produce high whites, is not the best course of action.

Breed it if you must, but I would look out for something more visually stunning to try and pass on the genetics of that animal.

I'm just fearful that what has happened to the pastel gene is going to start happening to other morphs. It is rare for me to come across a stunning actually YELLOW pastel. I believe this is party due to the fact that people are not breeding them selectively. They are buying the cheapest animal and breeding for low quality pastels (AKA: $$$). Most of the pastels I see at shows nowadays are a disgrace to the pastel gene.

Now I'm not trying to say that the variations within morphs are not valuable; for example the Pied gene varies greatly and I love both the low white and high white pieds. The problem occurs when a pastel doesn't appear much different than a light blushed normal, or a calico with so little white it might as well be a normal. I actually love the variation within the pastel gene: lots of blushing vs. very little blushing. But the browning out of pastels is what is really prevalent as an undesirable trait. So why, if it is so undesirable, do I see 90% of pastels look browned out after their first shed? It should not be that hard to find a pastel that is actually yellow and only develops some slight brown spotting as it ages.

So for calico the most desirable trait is that high white speckling. So why would you continue to breed low white calicos? I'm not trying to tell you what you should and shouldn't breed. This is completely up to the individual. I'm just very interested in this conversation of breeding less than desirable animals.