Artists and poets alike have been unable to agree on Diane's hair color. I had always thought that it was strawberry blonde, a color between red and blonde, because of a locket at Anet.
Diane has been in the news since 2009, when it was discovered that the cause of her death was drinking a gold elixir that was popular during the 16th century. Her hair was analyzed and found to contain extremely high levels of gold. It was also thinning, as I wrote about in A Portrait in Black and White, a symptom of gold poisoning.
Below is a close shot of Diane's hair. Quite a remarkable color for a woman over sixty!