Isaiah 1:18 says, 'Though your sins are like scarlet, they shall be as white as snow; though they are red like crimson, they shall be as wool.' Before a person repents and is baptized in the name of Jesus Christ, his sins are like scarlet and crimson. They are bloody stains on his inner man. But when a person receives forgiveness of sins by obeying the Acts 2:38 plan of salvation, he is washed and clean like bright white snow or wool. It is simply an analogy. We hope this helps you understand.