I've seen both too. Some hold more of the yellow and grey/white contrast longer and others tend to just get yellow kind of like how boas do. Mine is only about 500g so I have a while to go to find out how his contrast holds up. I'd be interested to see if it's just random or if certain lines could be traced that seem to hold up the contrast longer. Now I'm interested in seeing a thread of cg/bananas along with their age/weight. I'm a big fan of the freckles!