When I recently got an LE trade-in M&P40 1.0 I replaced the RSA. The one in the gun was green and so was the replacement. I just checked my nightstand gun, another M&P40 1.0, and the RSA is blue...it may be the original one and I bought the gun soon after they came out. I need to replace that one.
You're right about the mild recoil. The M&P40s and M&P45s are known for that. My M&P45s recoil less than my 1911s too.