Fig. 6. Chromaticity diagrams depicting mature and immature Banksia attenuata flowers. Chromaticity contrast (relative to mean immature chromaticity) is plotted in Maxwellian coordinates (see Kelber et al., 2003). (A) Chromaticity for extant honey possums; (B) chromaticity for hypothetical honey possums with L cone _max at 580 nm (_max values beyond this being implausible for rhodopsins). It can be seen that this long-wave shift makes the immature and mature chromaticities less distinct from each other. Note that the mature samples lie on the left (M cone side) of the immature samples, whereas for human vision, they would lie on the right (L cone side).