Question

How to produce a true breeding black rose

Answer 1

Both male and female parents have to have black as their recessive and dominant allele for their offspring in order to have a true breeding black rose. If it was between red and black, black would be B and red would be b. The male would have BB and the female would have BB. If you used a punnett square (look at pic) you can tell that it is true breeding by having BB, BB, BB, BB.

Hoped I helped!

Answer 2

In Some say that black roses do not exist, but apparently there are black roses in Turkey, but only during the Summer, when the dark crimson turns black.principle its possible  to genetically engineer