I'm still on the fence on whether I'll return my Colorsoft or not.
I've had it for almost a week now and it does have the yellow band at the bottom but it's not that noticeable (to me) and it sometimes disappears, depending on the lighting and the settings. What bothers me most is that I paid 300 euros for it so I expected it to be perfect or at least spectacular. I've grown to like it though and I've decided to read on it for another week and see how I feel about.
Amazon sent me an email following my one-star review on the French website and they said they would refund me if I wanted to but couldn't replace the device as it was no longer available.
The funny thing is that I was dead set on returning the Colorsoft so I ordered the Kobo Libra Colour, got it yesterday and now I love both devices.