Using uniform coloring in MatrixPlot

Question

I have a rectangular matrix, which is m-by-10. Each element is either 0 or 1. I would like 0 to correspond to white elements, and 1 to red elements. This works fine if m = 100 or similar small values:

m = 100;
list = Table[Table[RandomInteger[], {j, 1, 10}], {i, 1, m}];
Tally[Flatten[list]]
MatrixPlot[list, FrameTicks -> None, ImageSize -> {300, 300}, 
 ColorRules -> {0 -> White, 1 -> Red}]

However, if I choose m = 200, the coloring becomes strange and no longer only white or red:

m = 200;
list = Table[Table[RandomInteger[], {j, 1, 10}], {i, 1, m}];
Tally[Flatten[list]]
MatrixPlot[list, FrameTicks -> None, ImageSize -> {300, 300}, 
 ColorRules -> {0 -> White, 1 -> Red}]

Why do I see orange if each element is either 0 or 1? Is there any way I can correct this so that the only colors that appear are white or red?

Setting ColorFunctionScaling -> False does not seem to correct the problem:

Answer 1

Seems that the automatic setting of MaxPlotPoints is too low. You can set it to something high (or even Infinity) to get around this.

m = 200;
list = Table[Table[RandomInteger[], {j, 1, 10}], {i, 1, m}];
Tally[Flatten[list]]
MatrixPlot[list, FrameTicks -> None, ImageSize -> {300, 300}, 
 ColorRules -> {0 -> White, 1 -> Red}, MaxPlotPoints -> \[Infinity]]

Answer 2

As belisarius commented you can use ArrayPlot, which does not compress the range of the data.

list = RandomInteger[1, {10, 300}];

ArrayPlot[list, ColorRules -> {0 -> White, 1 -> Red}, 
 PlotRangePadding -> 0, ImageSize -> 600]

Perhaps better in this case you can also build the image raster directly:

Image[ list /. {0 -> {1, 1, 1}, 1 -> {1, 0, 0}} ]