1) Color is predetermined genetically.
However, what you see when a Shih Tzu is a newborn and then a young puppy is not his final genetic color.
2) Most of the time, final color can be seen at about the 1 year mark;
though smaller less dramatic changes may still take place over the years. In some rare cases, surprise changes can take place much
later, well into the adult years.
4) Not every Shih Tzu will have a color change, but most will.
It can range from very slight such as a patch of color darkening or be very dramatic such as completely new colors coming in or a certain color fading away to be replaced by another.
5) Color changes can take place during the newborn phase
and for this reason the AKC allows a breeder
to make changes to a dog's color listing on his/her AKC registration up to 3 times.
6) Just about any color change can take place.
Colors can lighten, darken, just a few hairs can turn into much larger patches, a certain color on a double color coat or a tri color coa
t can completely fade away, etc. The only limits on what cannot occur would be colors genetically ruled out (not in the dog's bloodline).
7) There is nothing that can be done to stop a color change, so do
know this if you fall in love with a certain color on a Shih Tzu puppy; most likely he or she will indeed look different as they mature. The good news is that all Shih Tzu look just as beautiful as before or even more so!
8) Aside from natural color changes with this breed, there are also other elements that can cause the coat to become tinted differently. The most common cause is excessive sunshine; too much sun exposure can cause a 'sun burning' most often seen with darker colors; they can take on a red tint. In some cases, tones will change seasonally, with slight differences seen from winter to summer and back again. This may be minor and only noticed when looking back at photos.
To prevent tinting changes due to sunlight, use a quality leave-in spritz. A good leave-in product will also help prevent tangles, static and contact friction which can lead to split ends.