I bought a brand new Shindy maste(which is actually a Nissin) and it came with a black lever.The stock B4's silver lever was a direct swap.
Much like cars,many bike parts arent proprietary to the make,rather they are sourced from specialty manufacturers....Nissin,Brembo,Tokiko,Dana Spicer,Borg Warner,ect....that sell similar (if not identical) parts,to many manufacturers.