DcDc animals tend to be white in color. The base color is still there, but it is removed by the Dc gene. This gene works similarly to the roan gene.
Dcdc animals tend to vary in color, from very light to quite dark. But, you can usually see the color to them. Black based Dcdc animals will be gray and red based Dcdc animals will be tan in color.
This animal is ee, ss, Rr and Dcdc. She is Red base, recessive spots, roan and diluted.
This animal is Ee, ShS and Dcdc. Black base, Hereford marked and diluted. Notice she is a lot lighter than the 1st cow, but still dark enough that you can see the white face.
The rear calf is also a Dcdc calf, where as the leading 3 are dcdc, that is not diluted.
Dbdb animals will be darker in color than there homozygous counterparts. Dark gray for the black based animals, and light to golden red for the red based animals.
Here is a good example of a Dbdb animal. Notice she has a more goldeny or orangey tint to her coat. Bred black she may throw grey and bred red she may throw a light red.