Currently there is a debate about the correct color for the thylacine, some arguing that the traditional lighter sand yellow representation is incorrect and is a result of long faded museum specimens. Robert Paddle in his book “The Last Tasmanian Tiger: The History and Extinction of the Thylacine”, put forward the idea that they in fact varied not just in color but size as well based upon the area that they were located. Coastal tigers being larger then their inland cousins and the tigers in the south west being smaller and of a much more gray color (as above). Some male tigers were reported as being exceptionally large, up to 8ft from nose to tail! The more standard size being around 51/2 ft. I did come across a replica scull that was much bigger then the one that I have in my possession and the ones that I have seen in the museum examples. The owner of the scull assured me it was to scale.
This localization of size and color results from varied diet and climate, the south west being wetter and with less game availability the other regions. We can never be sure of this without the identification of specimens. My own view is that Paddle may in fact be correct and that if we are able to image a tiger it is more likely to be in the south west and may well look like the above image.