They're just saying, there's no guarantees. There's more likelihood that if you have a male with looks you like, and the female's father and brother look very similar to the male's looks, you're more likely to get that look you want than if you breed two very different colored bloodlines together.
But still, it could still vary. Different chameleons = different traits.
It's obviously going to be more likely to come out blue if you're breeding Nosy Be to Nosy Be, rather than Ambilobe. There's just a lot more variations to consider with the colourations involved in Ambilobes.
But you also have to keep in mind that it's harder to judge the colourations in the bloodline of the female if you haven't seen a lot of her male relatives.
Keeping that in mind though, there are also lots of variations involved even in a single male. Their colourations changes over time, (both my boys have changed quite a bit in the year that i've had them), so judging bloodline colourations by a single picture isn't necessarily an accurate prediction of what you're likely to get from a breeding either.
I just dont think it is quite as basic and scientific as the genetic equations you see with other species. With the "big letter plus little letter equals this" predictable math. I'm assuming that's what you were after.
Since it's more a changing and changeable variation of colours, I just don't think it works in a predictable way like that.
There are "chances are more likely you'll get something with high red" types of assumptions, but no certainties of getting a clone of mom or dad.
You just have to go in with "chameleons look cool, period" kind of expectations, and if you have cool parents, chances are better you'll have cool babies. If you have a male with looks you're after, and the males in the female's lines have looks you're after, chances are "more" likely you'll end up with a baby with looks you're after. But never any guarantees.