The Panties.RGB slider can be used to recolor the item. Please use bright colors; dark colors will look ugly (due to hardcoded shading patterns).
Version 2.0 of this item has been repackaged as a vanilla SDT import. It isn't truly vanilla, because it uses the CostumePanties modtype. It therefore requires @sby's template extension mod (which is included in both of the standard Loader packs). The mod is "vanilla enough" for most gameplay purposes -- it can be loaded via moreClothing and recolored via dialogueActions.
If you would like to play with the original 1.0 version then you can find it via the Version History tab above. 1.0 is a Loader Mod which uses the Loader tab for hue-shifting.