I have an M3 and I can't say I notice a tint. If it is there it must be quite subtle. What I do notice, and like quite a bit, is that the rangefinder patch does not flare to white like my M6 does.
I do find it somewhat amusing. When they built the first M3 there were no problems but as time progressed, and the M was "improved", the rangefinder began to flare. Thank goodness for improvement. There would not be a thing to write about without them.