We know the color of both Harry's and Hermione's eyes but what color are Ron's eyes? Was it ever stated in the books?
MA: What color are Ron's eyes?
JKR: Ron's eyes are blue. Have I never said that, ever? [JKR covers her eyes.]
MA: They’ve been dying for us to ask this.
JKR: Blue. Harry's green, Ron's blue, and Hermione's are brown.
Source: Melissa Anelli and Emerson Spartz. "The Leaky Cauldron and Mugglenet interview Joanne Kathleen Rowling: Part Three", The Leaky Cauldron, 16 July 2005
(found via accio quote)
It was stated in Harry Potter and the Deathly Hallows (when they were destroying the Horcrux locket) that Ron's eyes are blue.
Harry thought he saw a glimpse of scarlet in Ron's eyes, but when the Horcrux died the narrator said they...
... were no longer red at all, but their normal blue.
Chapter Nineteen: The Silver Doe