many daylilies will fade in color during the course of the day. that is the usual effect of the sun. some daylilies do not fade. some get darker. this is Trahlyta. the image on the left is morning, the right is evening. daylilies either have their own sunscreen or not. actually while most of the petal got darker i do think the dark areas of the eyezone may have faded a bit. and just in case you are wondering is it the same flower then look at the pattern of the stamens and pistil. same.