Finally, there are a few elements within the simulated world that would have to remain in colour, as was done in Sin City and Schindler's List. The most obvious ones are the red and blue pills and the woman in red, whose colours are referred to in dialogue and which it would be appropriate to show. The computer displays I'm tossing up about. I want to have both the computer displays in the Matrix and the Matrix feed in the real world either both green or both white. Suggestions for this or other elements that you think should be coloured are welcome.
I think the matrix code should always be seen as green. The concern really is moving between the real world and the simulated world...For example when Morpheus offers to show neo what the Matrix is we see a close up of Neo's face as they 'plug him in' then some fiddling about then we cut back to a close up of his face only to see that we are looking at him in the matrix, as the camera pulls back.
Cutting between colour and B/W might ruin the 'suprise' element of the shot. It might be best to quickly fade the colour from the shot as the camera puls back.
And in terms of other computer displays, they should probably be B/W - since what they are showing is the simulated world - No computer inside the matrix would show anything of the 'real world' - which is in colour.
There probably shouldn't be any colour at all until the red pill / blue pill scene. Then you could slowly introduce colours [woman in the red dress et al] until eventually Neo sees the matrix in green code.
Also interesting in that Neo ingests the red pill only to wake up seeing nothing but red at first. and then a world of colour. Keeps the 'alice in wonderland' in play :) "one pill to make you coloured..."