I love purple tights (dark ones, more plummy I suppose, the brights just arent for me) I often pair them with a long length dark grey sweater or dress, I think black would look great too!
I usually dont do much in the way of loud accessories with it though, if the dress/sweater requires a belt I'd do pretty simple one and boots, maybe with a long necklace or two OR a pair of larger earrings and a neutral bag.
yes, dark purple tights should be a staple along with navy and hunter green. so refreshing and a break from opaque black if you live in a cold climate (and wear tights often). i also love grey and wool or cashmere blend tights for adding texture to a look.
dark purple tights are hot.. if you're wearing a black sweater dress i'd suggest either a black or grey coat, i would not add to many accessories.. one or two flowing necklaces, maybe a patent bracelet