The basic look offered on Rainbow at the genes affecting Havanese colour has hopefully given you a few insights. In an attempt to make it as understandable as possible, I have included a condensed Colour Chart in a one page reference guide as to what the different genes are and what they do. The genes included on the chart are the same ones we just reviewed: A, B, C, D, E, G, K, S, T, and V. The colour chart does not have all the combinations possible in Havanese, but it does show most of the basic ones.
It has been asked how it is possible for the Havanese to have so many colours when the breeds in its background, and related breeds, are white only, such as the Maltese, Bichon Frise etc. This is a very interesting question and one that bears looking at. Many of the breeds that are currently only accepted in white were not always historically so. See Maltese History for information on the history of coloured Maltese. The Lowchen and Bolonka which are related breeds do also come in many colours. In fact, a white coat in the Bolonka is undesirable. Although preferred the Coton is permitted patches of colour. Cotons with coloured patches usually lose that colour as they mature, very likely due to a strong chinchilla gene or a similar modifier. The Bolognese as well historically has colour in the background. We are told that the Bolognese is essentially white in color and must give an over-all white impression. This wording appears to indicate that other colours may be blended. One must also keep in mind that other breeds may have played a part in the development of the Havanese, such as one theory which links it to small poodles of assorted colours (see the Havanese History page). There is a rich history of colour behind the Havanese, some which we know and much which we do not. We will never know all there is to know. There is always more to learn.
Occasionally we hear comments about "new" colours that are popping up in Havanese. The colours are not really new at all. They have always been there, but have just been hiding. They are very likely the result of recessive pairing. As there get to be more Havanese, the likelihood increases of a recessive allele meeting a matching recessive and getting the chance to be expressed. Remember: As Francis Greer said, "Genes don't go away, they hide."
The interplay of so many genes and possible variations is what makes Havanese colours so intriguing but also complicated. Even so, colour in Havanese is not as unpredictable as it first seems. Even only one litter can tell you a lot of information about the potential coat colour genetics of the sire and dam. Watching a litter as it grows to maturity can tell you even more. If you want to test your knowledge and see how far your sleuthing skills can take you, give our Litter quiz a try.
This brief colour study is by no means complete nor does it show all possibilities; it is meant only as a basic overview of the genetics involved in Havanese colour. The information contained herein is colour inheritance as I have come to understand it through my studies. As time goes by, changes may be made and definitions may become clearer as we learn more and more about the genetics behind coat colour. Anyone wanting to pursue more in depth study can do so as they wish.