Bright colors of Thai silk.
There is evidence from archaeological sites in Northeastern Thailand that silk production there may pre-date the start of sericulture in China. Despite this long and rich history, the cottage industry was in something of a decline by the end of World War II, when the American Jim Thompson supposedly revived it. That may have been a bit of self-serving PR, but the Jim Thompson Thai Silk company definitely invested heavily in developing a quality silk supply, and continues to do so.
Traditional Thai silk is a bit heavier than the Chinese variety. It's best suited to skirts, jackets or upholstery rather than shirts or sheets. You will find it on sale just about everywhere you go in Thailand. Aside from the Jim Thompson shops there are several other reputable (and probably cheaper) places around Bangkok to purchase Thai silk items and fabrics. The Thai handicrafts 'superstore' Narai Phand is one place you should definitely give a look. They have a wide variety of ready made garments, as well as a selection of traditional Thai silk fabrics for sale.