To a lesser but still substantial degree that's also true for not so great scans in DjVu/PDF, btw. Except there it's something like ScanTailor, unpaper or k2pdfopt instead of Sigil.
The new zoom to comic panel feature is also quite neat for what little manga I read on my device. I actually have an Izneo subscription right now (mainly for Franco-Belgian comics in French), but I use that on my laptop. I wouldn't want to lose the color.