Dude, you are suggesting that only black cows can birth black cows? Only red hens can lay eggs that have red chicks in them?
I have white female friends that have black children. I have black female friends who have white children.
God didn't command that every creature of every color come on board the ark. Only two of each KIND. This excluded humans, of course, cause we know that EIGHT humans were present!
God saved Noah and his family because they were the only ones found righteous in His sight.
Gen. 6:6 And it repented the LORD that he had made man on the earth, and it grieved him at his heart.
7 And the LORD said,
I will destroy man whom I have created from the face of the earth; both man, and beast, and the creeping thing, and the fowls of the air; for it repenteth me that I have made them.
8
But Noah found grace in the eyes of the LORD.
9 These are the generations of Noah: Noah was a just man and perfect in his generations, and Noah walked with God.
10 And Noah begat three sons, Shem, Ham, and Japheth.
11 The earth also was corrupt before God, and the earth was filled with violence.
12 And God looked upon the earth, and, behold, it was corrupt; for
all flesh had corrupted his way upon the earth.
13 And
God said unto Noah,
The end of all flesh is come before me; for the earth is filled with violence through them; and, behold,
I will destroy them with the earth.
God did not then go against what He said and then save a male and a female from every race! They weren't righteous, if they even existed!
Fact is, you have no Biblical proof that any other race other than whatever Adam, Eve, and Noah were existed before the flood. NONE.