Help! I've gone orange!!

[biryani]

Did my slap today as usual: primer, foundation and a bit of powder-went out for a few hours and when I got back and looked in the mirror I'd turned orange and sort of cakey. Is it the weather? My skin is greasy as a rule. Any ideas?

It's probably the foundation oxidising.
It would be down to one of the following or a combination: pH of the skin, humidity, temperature and how oily your skin is.