Interesting as a set of Pullman cars I've got has been continuously been on several layouts over the last 50 years, all purchased at the same time, 3 belong to the barnstaple set. Once they all were the same shade, now all different, some got lighter some got darker, one or two have different shades each side. All have been in darken rooms no sunlight, but assume even natural light fades them, also wonder if LED light has any effect as noticed it's more prominent recently or it could just be age at 56 years