The sandal straps use the Footwear.RGB sliders. The soles use the Footwear.RGB2 sliders.
Moderator's note: This mod slightly alters the shape of the girl's feet, so it originally consisted of four vanilla imports (SWF files) - one for each skin tone.
I've repackaged it as a single Loader import (MOD file) which switches between skin tones and tan settings as needed. If you encounter problems, then you can use the Version History tag (above) to download one of the "legacy" SWF files.