The thought of cheating has crossed my mind, but then I would just be fooling myself. 
The hues which I failed didn't look right to me but after shuffling the color squares around that area several times I couldn't decide if they looked right or not. I'm happy to with whatever score I got. 
+1. I had the same score as you, but my 4 errors were in the green-blue transition. I also note that on my display, the color bar they show with the score is noticeably striped, even after display calibration. It appears to be a brightness, not hue, issue.
And note to self: I need new glasses...
