Pronotum colour

Pronotum colour

Observation - Pronotum colour - UK and Ireland. Description: Poor quality pictures but I was interested in the difference in the pronotum colour on these two ladybirds. I know that ladybird colours darken with age (and if I stare hard enough I can convinced myself that the upper ladybird is lighter overall) but th

Poor quality pictures but I was interested in the difference in the pronotum colour on these two ladybirds. I know that ladybird colours darken with age (and if I stare hard enough I can convinced myself that the upper ladybird is lighter overall) but the contrast between elyta and pronotum colour on the upper (male?) ladybird seemed quite stark and I wondered if there is something else going on.

Anyone have any ideas?