The Dominate White Canary

Dominant White Ground

The Dominant white is the most common white in canaries. The Dominant white can be easily identified by the slight yellow tinge on the Shoulder or Butt of the wing.  This yellow is not present in the recessive white.
All birds born yellow do not carry any gene for white.
When breeding the Dominant White you should not bred White to White as on average 25% of the young will die by inheriting a lethal gene. You should breed White with Yellow or Buff. This on average would give 2 White chicks and 2 Yellow/Buff chicks.

"The Dominant White appeared on the showbench in he 1920's. This version of white canary is a dominant heterozygous version and therefore, in single dose is dominate to all other forms of lipochrome (fat based)  coloring. Consequently, a bird is either a dominant white or not; it cannot carry the factor. The pairing of dominant white to dominant white is NOT recommended. When the mutation is present in double dose the chicks becomes nonviable and cannot grow to maturity.
The dominant white bird should only be paired to a non-intense (buff/soft feather) bird." Walker
It is sometimes difficult to determine if the bird is D (dominate) or R (recessive). If you are going to breed the bird you need to know to avoid non viable chicks that die.To determine; Examine the fat of the bird, normally visible above and below the rib cage. In Recessive White the fat is White and remains so regardless of the diet. The recessive white bird will always remain clear white.  
In dominant white the fat is yellow. Yellow fat will change according to the diet.
You also need to determine the bird's feather type..soft feather is buff or hard feather.. for breeding purposes.