This is always an interesting one. I had someone, awhile back, ask about breeding a blue diamond to a beige. They wanted to get, more blue diamonds, of course.
Because blue diamonds are recessives, that's unfortunately not how it works.
When you breed a beige, you have the opportunity of getting beige or standard kits.
When you breed a blue diamond, depending on what you breed it with, you have the opportunity of getting blue diamonds, sapphire violet carriers, violet sapphire carriers, and standard violet & sapphire carriers.
Now, a beige is a dominant gene, so whatever you breed it to, you will get beige or standard (plus the possibility of additional colors, but at least those). Since a blue diamond is a recessive, and a double recessive at that, for you to get ANY color other than a standard violet & sapphire carrier, you would need to breed it to a chin that at least carries (if not expresses) sapphire and violet. That's because to get a violet, sapphire, or blue diamond, BOTH parents must express or carry the gene. Got it? Good.
So, since the beige chin in this example is just a regular beige and does not carry any other genes (and yes, we know this), there's no way for a blue diamond, or sapphire, or violet, to be produced. In fact, the only options are a standard grey that carries violet and sapphire, or a beige that carries violet and sapphire.
I often can explain this to people until I am blue in the face, and many people don't understand, until a few litters later, when they only get beiges and standards, and don't understand why the male didn't reproduce the pretty blue diamond color! He's a blue diamond, come on, he should produce kits that color! Not quite. There needs to be an understanding of basic genetics to understand why this works the way it does.