They don’t change the books that often, it is not yearly so you should be ok.
Bias, yes, but you can lose based on not a DQ too. For example, my kid showed a bird that was supposed to have light grey under feathers. Something we didn’t check. Bird didn’t have this, it is not a DQ, but...
If it is in the realm of possibility for you, the largest poultry show in the country occurs in Columbus, Ohio in November every year. It is a great place to learn and see many examples of the breeds with thousands of entries. This show is called the Ohio National http://www.ohionational.org/
Is the show an APA show?
If so, I recommend you buy the book of standards from their site. It states everything the bird should have, and specifically what would be a DQ.
The book also tells you which colors are accepted colors.
There is a lot of detail in the book and you can learn a lot.