Well, googling anti-Roma law in conjunciton with the United States informs me that in 1998 in New Jersey the last anti-Roma law in the US was officially rescinded by their govenor, so while that is not a 100% reliable fact check I suspect that kind of law must have existed in other US states too, and had effects at some point. And these "positive" stereotypes exist here too, but of course there is no contradiction between that and the negative ones, these things usually co-exist and even reinforce each other. I mean, it's like the idea that black people somehow were more "musical" than whites and such.