There are many myths surrounding the breed, especially whites, let me dispell those for you.
1) White Boxers are all deaf - FALSE
This is a common mis-belief. White boxers can be prone to deafness, but this also occurs in Reds or Brindles, or any other breed of dog.
2) White Boxers are not accepted as pedigree - FALSE
White Boxers can be registered as a pedigree with Crufts.
The German Police used to use Boxers as messenger dogs. Due to the nature of their task, a dark dog was more preferable than a white dog as darks were less visible when travelling at night. Sadly this stigma has stuck and some breeders still dislike white boxers. There is no need.
3) Boxers are aggressive - FALSE
This is not a denominator of the breed. Any dog can be aggressive, from Poodles to Great Danes, it is dependant on their treatment and environment.
4) Boxers are boisterous - this isn't strictly true or false, again it depends on the dog. Be aware that the majority of Boxers weigh between 25-32Kg, and due to their weight can be extremely strong dogs. Boxers also get excited, and can therefore get a bit clumsey.