4:4 meaning that 100% of their offspring will be dominant in having freckles. Assuming that you mean that both parents are heterozygous dominant, we can make a punnet square to get our answer.
| F | F |
F | FF | FF |
F | FF | FF |
The mother's alleles are on the left of the roughly made punnet square, and the father's alleles are on the top. The four offspring all have FF, or dominant alleles. This shows that 100% of the offspring will have freckles.