This mod works only with the Tanned skin tone. The Tan options (Full, Bikini, etc) should not be used because the custom breasts will not be recolored while the girl's torso will be recolored (creating an unsightly seamline). There is also a shape-hint error in the [98...112] range which causes the outlines to drift across the breast fills. You can avoid this error by simply using the "T" hotkey to switch between the preset Breast sizes.
Unlike @sby's superBreast mod, this mod directly replaces the breast sprites instead of moving or stretching them. Therefore clothes will not fit. You should use this mod only if you expect the girl to remain topless.
Moderator's note: I'm uploading this mod for archival reasons, in spite of its technical limitations. If it proves popular then I can prepare an updated version which supports basic tan options and multiple skin tones.