can choc and white (yellow)

Question
QUESTION: y cant yellow and chocolate be breed ?what is a dudley??

ANSWER: You CAN breed a yellow and a chocolate, but you need to know what colors each dog genetically carries.  

A Dudley is also known as a NBP (No Black Pigment) Yellow, which is a yellow lab with chocolate pigmentation.  This type of coloration is fine for pets, but since it is a disqualification in the show ring, reputable breeders try not to produce this color.  And because they try not to produce this color is the reasoning why you would not breed a yellow and a chocolate together, because it runs a high risk of producing the NBP Yellow dog.  

But a NBP Yellow can also be produced when you breed 2 black dogs that both carry chocolate and yellow.  

Here's another way to think about the colors of labs:

Black is dominant.  Black fur/Black pigment on nose, eye rims, lips, pads, etc.
Chocolate is recessive.  Brown fur/Brown pigment on nose, eye rims, lips, pads, etc.

Yellow is a gene that turns off the "color" of the fur.  
A correct yellow dog has the light fur due to the "turn off" gene, and the black pigment nose, eye rims, lips, pads, etc.
A NBP yellow dog has the light fur due to the "turn off" gene, and the brown pigment nose, eye rims, lips, pads, etc.



---------- FOLLOW-UP ----------

QUESTION: my yellow is almost pure white and my choc has a pink nose  does this mean the nbp will make them whiter if i breed or copy the father a red/brown ??

Answer
No, you don't know what color they carry genetically unless you do a DNA test.  So unless you do that, I WOULD NOT breed the colors together.  And NO, this will not make the yellow lighter or definately reproduce the father's color.  And if the father truly has a pink nose, that means he has totally incorrect pigment and should not be bred.

And if you have not done the health clearances (OFA hip/elbows/heart, CERF, PRA testing) I would not plan a breeding.  And if the dogs have not proven themselves at show or at performance events, I would not breed them.