Hello, Attached is a script that when run from ipython --pylab with your backend setup for 'QtAgg' reproduces a bug I am seeing. If you run the plot, you'll see a line plotted in blue as expected. Then when the same figure is updated by blitting, the line turns red. I tried this with green and it stayed green, but yellow went to cyan. It seems that the byteswapping that is necessary for displaying colors correctly in Qt is happening during a normal plot, but not when blitting. I tried going through the code to determine the problem, I can only guess that it lies somewhere in the FigureCanvasQTAgg.paintEvent, since that's where I see to_ARGB etc. Sorry I couldn't locate the bug precisely, I find it very difficult to thread my way through all the backend classes. Glenn