What do I do about young impatiens turning white?

I planted impatiens from seeds in a small greenhouse kit, they sprouted well, and I just transferred them to a bigger pot. We put them outside, we live in upstate NY and it was about 60' and sunny, some of the leaves turned white. I don't know what caused this and they are gifts my youngest kids plan to give for Mother's Day...please help. I don't want to start over again (no time)