I will not hesitate to rip and fix (my quilts are quite imperfect enough without my making intentional mistakes), but I seriously doubt I'd bother with that one. The fabrics are so similar that it's honestly not that noticeable, and the controlled-scrappy nature camouflages it. It's also for a six-year-old who just wants something Mommy made. He's not going to be whipping out a scorecard. ;)
In this instance, I vote leave it.
ETA: Nice job matching seams. I know there are no Quilt Police here, but I can't help noticing careful workmanship and yours looks pretty darn precise. ;)