OK with some help from @Henk69 's chicken site:
" Columbian factor - symbol Co.
Columbian chickens are more groundcolored looking.
For roosters the most obvious effect is that breast and wingbands are not black but groundcolor. The groundcolor is also more even. The hen loses the salmon breast coloring by this effect and becomes more warm in groundcolor. Her black pattern is restricted to her back and saddle, if not further towards the tail."
"Columbian is not just a black restrictor, it also shifts black pigment. Hens with columbian get a tail that is more black and with more green sheen"
"It has more effect on males than females, especially their backs and saddles."
Maybe Henk69 will chime in on the descriptions
" Columbian factor - symbol Co.
"Columbian is not just a black restrictor, it also shifts black pigment. Hens with columbian get a tail that is more black and with more green sheen"
"It has more effect on males than females, especially their backs and saddles."
Maybe Henk69 will chime in on the descriptions