"Faithful" is another Picture Style for reproducing the colors of the subject exactly as they are. The "Faithful" Picture Style is set to record colors that are colorimetrically the same as the actual colors of the subject under 5200K lighting conditions.
Like the "Neutral" Picture Style, it emphasizes further image editing in your computer. Color saturation and contrast are deliberately toned-down. However, rather than trying to provide a distinctly neutral color appearance, images in the Faithful setting will have a warmer "look" that may provide a better starting point with various subjects, including still life images.