Addition-Elle has come out with the latest version of their Perfect T-shirt Bra. It is listed as “off white” but looks like a pretty baby blue. It also comes in black. Sizes offered are 38B to 44DDD (and there is a G and H option sold separately). They are pretty pricey at $54.99 but are currently on for buy one get one 40% off — so about $22 off.
T-shirt bras are not just for t-shirts, they are great under fine knit sweaters too.