The freckles added by this mod are static. They do not respond to the "freckle density slider" nor the RGB sliders. The vanilla freckles are drawn in random locations, but these ones are not. You cannot recolor these freckles.
The freckles on the breasts will adjust to fit breasts of various sizes.
Due to a layering error, the freckles on the girl's right shoulder will be drawn on top of her clothing. Therefore you should probably use this mod with sleeveless shirts. Or just leave the girl topless if you'd like to admire all of the freckles :)