Unless the see-through button-down in question happens to be white or peach, there's no way flesh-colored undergarments will pass for real skin. So don't even try! It will look forced and awkward. It's better just embrace the sheerness with one perfect seamless black bra, which works with every cut and color. Just be sure it's made of smooth fabric before ordering, though, because lace looks lumpy under delicate silk.
A lingerie expert once told me that European women prefer their basic bras in white over nude because, should the straps show, it looks so much prettier. Although I still stick to frills-free light tan for tight white undershirts (there's just no other solution!), I've discovered this switch works especially well with a paneled top; because there are multiple seams, the outline of the bra blends right in.
Stop wondering why on earth you should pay over $555 for a sweater that's too hot for summer and too cool for winter—this is top you can wear all year! See, right now, it's the perfect thing to throw over a cropped long-line bra and a high-waisted skirt or shorts to weather deep-freeze air conditioning and chilly summer evenings. Then, come fall, you can layer a tissue thin turtleneck beneath straight through spring.
You can totally do this one like the model in the photo with a simple white bandeau; it's very cool, minimal and Calvin Klein-y. But might I also suggest trying the same streamlined shape in a contrasting color? The effect is sporty yet sexy, like something Kate Bosworth might have worn in Blue Crush.