The color is described as "light buff"
According to wikipedia "The first recorded use of the word "buff" to describe a colour was in The London Gazette of 1686, describing a uniform to be "...a Red Coat with a Buff-colour'd lining".[4] It referred to the colour of undyed buffalo leather, such as soldiers wore as some protection..."
In other words, "light yellow"
Yellow Daylilies are my favorite!