What colour is interchange yellow?

[DaveR]

Hopefully not quite as dumb as it sounds - although I have to admit...

Anyway, Mrs DaveR has decided she wants a yellow convertible. Yellow is seemingly more important than One, Cooper or Cooper S - but I might be able to help there

In some pics interchange yellow looks almost like a light citrus metallic and in others it looks like a pastel egg custard. Can anyone shed any light?

Thanks.