In this work, safflower (Carthamus tinctorius L.)-dyed textiles were taken as main research objects in order to study the degradation of carthamin, a coloring matter, under the influence of several color fading factors through two accelerated ways of light aging including UV and LED. The results show that hard and soft acidification effects produced different by products. Tricoumaroyl spermidine, as a kind of phenolamides, which was reported abroad as Ct4, was identified from safflower pollen grains for the first time by liquid chromatography-mass spectrometry (LC-MS) and could be used to distinguish between modern and ancient processes as a dyeing indicator. Taking two pieces of safflower-dyed textile relics from the Palace Museum collection as examples, the color fading mechanism was speculated out that the degradation of carthamin produced several products which increased the relative content of tricoumaroyl spermidine and resulted in obvious color fading and orange color of the front. The research result emphasizes that more attention should be paid to indoor pollutant acid air of volatile organic compounds (VOCs) for the same type of cultural relics.