I'm doing it again but this time I'm doing a preliminary sort, giving my eyes a rest and coming back to make any changes I think are needed before submitting. I think fatigue plays a big part when looking at a monitor, not to mention that when looking at light you have an after-image of the opposite colour which could affect this test.
[edit] "…when looking at light…" I just realised how dumb that is.
This time I got 8, so one more than last time, but this time my errors were all in the blue/red area. I got all the green/blue ones correct this time, so that is a bit odd. I probably have some difficulty distinguishing blue, but if the parts I have trouble with are changing I don't know how conclusive that can be.