How old is Chewbacca, anyway? Do Wookiees get gray fur when they are old?
Chewbacca was born 200 BBY (two hundred years before the battle of Yavin)
and would die 25 ABY (after the battle of Yavin) at the opening Yuuzhan Vong War; at least this was the expected death in the now non-canon Star Wars works. With the opening of episode VII, we learn it is Han that dies, not Chewbacca.
Wookiees in their prime tend to resemble the wooded areas they live in (shades of brown, tan or reddish brown), but are known to change colors as they age. There are recessive genes allowing for albino Wookiees, but those are very rare. Very old Wookiees would lose coloration becoming grey or even white hair in their very old age. Wookiees can live to be upwards of 400 years of age.
According to Disney canon, he was 180 when we see him in Revenge of the Sith:
He was a Wookiee, after all, and he knew passion. His were a proud people, a people who had lived for hundreds of years peacefully on their wooded homeworld of Kashyyyk until the Clone Wars. He had been younger then, just one hundred and eighty, and he had fought the Separatist battle droids. He had witnessed the betrayal of the clones and the beginning of the Empire. He had seen his people, his brothers and sisters, his family, put in chains and sold as slaves throughout the galaxy. He had been put in chains himself, and just the memory of it made a growl rise in his throat.
- Star Wars: Journey to The Force Awakens: Smuggler's Run - A Han Solo & Chewbacca Adventure
The Battle of Kashyyyk occurs in the year 19 BBY. The films in the original trilogy are each separated by a period of a year. The Force Awakens takes place in 33 ABY (30 years after the Battle of Endor).
Episode IV: A New Hope: Chewbacca is 199 years old.
Episode V: Empire Strikes Back: Chewbacca is 200.
Episode VI: Return of the Jedi: Chewbacca is 201.
Episode VII: The Force Awakens: Chewbacca is 231.
Therefore, assuming that Disney canon maintains the earlier tradition of Wookiees living ~400 years on average, Chewbacca is literally "middle-aged" in the original trilogy.
According to new information in Solo: A Star Wars Story, Chewbacca was 190 during the events of that film. As the film takes place in 10 BBY, Chewbacca is 200 years old at the time of the Battle of Yavin.
Empire takes place three years after ANH, Jedi takes place 4 ABY, and the new sequel trilogy takes place in 34 ABY
Chewbacca's age at various points in the series
- Episode III: Revenge of the Sith: 181 (RotS takes place nine years before Solo)
- Solo: A Star Wars Story: 190.
- Episode IV: A New Hope: 200.
- Episode V: The Empire Strikes Back: 203
- Episode VI: Return of the Jedi: 204
- Episode VII: The Force Awakens/Episode VIII: The Last Jedi: 234