I have just made a bride and groom using 50/50 modeling paste and fondant (white) I added flesh coloured gel paste. after a couple of days drying the figures went a very pale yellow colour. I have neveer had this problem before.

Any ideas why please?

AI've found that some colors lose their color quickly when exposed to light (doesn't even have to be direct sunlight). Green, yellow and orange are the colors that I've found most prone to that behavior, and flesh color is pretty much just diluted orange.

Anything with an American brand red food color in it will fade.  Something to do with their food safety laws.

It is a pain as i haven't time to make more figures. I used sugarflair flesh colour.
 

For the future, I've found steaming the figures helps keep the color from fading by sort of "setting" it.  Then I put a big box over them to keep them in the dark while they dry.  Maybe you can try it now to stop it from fading further?

Thank you i will try that x