Colour
I must admit to being a little puzzled as to the Yellow. But I know Tony had many contacts for his colour references. So presumably the cigarette card was either wrong or an earlier scheme.
John
The following photos from Christies Thursday 11th February 1999 catalogue.

And changed to Black and White.

The yellow is quite a possibility. A friend of mine has returned the mortal remains of a Vega Gull to the UK and has commenced rebuild to flying condition. This Gull was dispatched direct to Australia in 1938 finished overall in a glossy primrose yellow with mid to dark blue markings. What a pretty aeroplane that will be on completion.