I had been using Windows 8 and TortoiseSVN icons have been displaying properly, but after installing Windows 10 I can no longer see the icons for the files/folder status.
I deleted all my onedrive keys, installed latest preview etc and finally realized that the icons were working all along for some explorer directory views and not others.
In other words, medium, large, extra large, and tiles, but not list or detail. Since I don't want to learn all about how that works, I am just viewing my work directories as tiles for now.