A:Answer It's the other way around. The left joy-con is red, and the right joy-con is blue.
If you buy a "neon" Switch system, it comes with blue (L) and red (R). But this spare set is red (L) and blue (R). If you've already bought a neon Switch system, buying this set will leave you with one pair (left and right) of blue joy-cons, and one pair of red joy-cons.