What are the genotypes of parents and children, if parents with non-red hair have four children

What are the genotypes of parents and children, if parents with non-red hair have four children, one of them is red-haired. What sign will be recessive?

If out of 4 children only one carries this symptom, then most likely it will be recessive. In this case, the parents are heterozygous, and each contains in its genotype a recessive trait of red hair (a) and a dominant one – not red hair color (A). Let us prove this assumption with an example:
Parents Aa X Aa
Gametes of mother A, and Father A, and
Children AA (not red), Aa (not red), aA (not red), aa (red)
Thus, offspring from parents with non-red hair are obtained in a 3: 1 phenotype ratio, and one in four children will be red-haired.