Science has revolutionized lingerie with panties cut out with a laser (because they're microfiber, they won't run or fray), thus eliminating bumpy seams and bulky hems. The deep brown—trust us—will disappear under white because it blends so well with her skin.
You've Got Pale (center)
Made from superthin, razor-cut microfiber, the trim panties here are a good compromise, coverage-wise: roomy enough in back to look good under loosely woven white clothes but light and sleek enough for steamy weather.
Sweet Nothing (bottom)
If you're not yet a thong convert, this is a great try-out idea: It has modest coverage in front and narrow, unobtrusive elastic along the edges.