if the roo is pure for columbian then all will be columbian pattern.
The other problem is what base is he under the columbian... wheaten is very common in large breeds it is almost the default guess for any big chicken that is not black.
If he is wheaten but not pure for columbian, you might get wheaten duckwing roosters but the hens can be hard to identify between wheaten vs columbian.
dark brown is the most recessive base, so if you actually get wheaten duckwings from the above cross, use them to finally get darkbrowns in the third generation.
Edited by Kev - 2/19/16 at 12:40pm