Last I did color variations was June 28 when I published three versions of the new desk mats. I was pleasantly surprised to find them color-grouped a day or two later. At same time I went looking around at old color-groups that had always been wrong. For example a set of four tree skirts where the one color refused to group despite many manual requests plus even asking in the tech section of the old forum to please try to add that orphaned color version. Another was a set of eight pillows (yeah, I went a little crazy with that one) that had always been in multiple smaller groups instead of all eight together. Same with a group of cards I had, they weren't all in one group. Now everything is properly grouped together even though I didn't do anything (I had adopted a 'what will be will be' attitude for color groups). It was back at the end of June when I noticed this but hopefully all is still running smoothly.
