The young leaves of Elaphoglossum paleaceum are provided with a thick coating of amber colored reflective scales. Watkins et al. demonstrated that the reflective scales protect that species against photoinhibition. I suspect the same thing might be going on with Pleopeltis macrolepis, another species that it frequently co-occurs with at the same site and which also has amber colored reflective scales on its leaves.
Watkins Jr, J. E., Kawahara, A. Y., Leicht, S. A., Auld, J. R., Bicksler, A. J., & Kaiser, K. (2006). Fern laminar scales protect against photoinhibition from excess light. American Fern Journal, 96(3), 83-92.