I wish I had some first hand racer experience but do not. I can tell you that some snakes just don't like using the lay box, and with your racer, I might associate it with it being a more active species; one that might not have an enclosure to it's liking.
If you catch the eggs early, so they don't dry out, then there is still a good chance that they'll do well. As for discolouring, in my experience, they've all died off, but hold onto them until it becomes more obvious that they arn't any good. I know of plenty of examples where other people have hatched some pretty ugly eggs.

Good luck, I'm sure it's an interesting species to work with

Ian