There's no such thing as an "NA2 roof" or an "NA1 roof".
NA1 and NA2 are engine codes. The NA1 engine is the 3.0-liter engine that came on all '91-96 NSXs, plus the '97-05 NSXs with automatic transmissions. The NA2 engine is the 3.2-liter engine that came on all '97-05 NSXs with manual transmissions.
The contrasting black roof was used on all NSX fixed-roof coupes, available '91-01, with the exceptions of the '99 Zanardi Edition and a few late-'94 Brooklands Green cars. (Coupes were rare starting in 1995.) The color-matching roof was used on all NSX-T models, '95-05, and also the previously noted '99 Zanardi and '94 green exceptions.
The above is true of all North American NSXs.
As you can see, some NA1 cars have contrasting black roofs, and others have color-matching roofs; some NA2 cars have contrasting black roofs, and others have color-matching roofs. Thus there is no correlation between the engine codes and the roofs.