[Structure] micron-sized dimples lined with chitin layers [Example] Papilio palinurus, emerald swallowtail butterfly wing scales[48] [Mechanism] 
Selective mirrors
D i f f r a c t i o n g r a t i n g
S e l e c t i v e m i r r o r s
P h o t o n i c c r y s t a l s
C r y s t a l f i b r e s
D e f o r m e d m a t r i c e s
R e v e r s i b l e p r o t e i n s