Hi Mike,
Both colours were used. The front wheel has 36 spokes and the rear wheel 40.
I had one in olive drab with brown wheels. Not overpainted but original. Most original bicycles had black paint underneath the green or brown paint.
Hope this will help.
regards,
ramon
email (option): noahlevi6@hotmail.com
I'm sure I saw the brown colour described in some official document somewhere as being similar to 'tea with a splash of milk'. 
so that would be a milky white as i like my tea weak
email (option): roger.beck@node6.com
In the Low Countries we call milk in the tea: "The Great Tea Murder"
I remember the parcels from the food droppings ("Operation Manna") that contained all kinds of goodies: Welfare biscuits, chocolate bars, powdered eggs, Irish stew, corned beef and also tins marked "Tea". But that was powdered tea ready mixed with milk powder..
. We tried to sieve it out, but to no avail, sorry...
Hans
email (option): viaconsu [at] planet [dot] nl
I used to work with an ex-RAF chap who called tea with milk and two sugars 'NATO Standard Tea' I think the colour of the paint refers to the tea as described by the GOONS. Thick, Luke-Warm NAAFI Tea.