Late reply, but I now do a lot of reading on my Nexus 10 tablet, having used a Sony ereader before but wanting a bigger screen.
I use a cover-up anti-glare screen cover which does a lot to make the screen look a lot like a color ereader – nice matt surface and little/no reflection. Maybe they do something similar for the Kindle Fire, this is the one I have:
http://www.amazon.co.uk/Cover-Up-Google-Tablet-Anti-Glare-Protector/dp/B00AAUDASE/ref=sr_1_7?ie=UTF8&qid=1385468511&sr=8-7&keywords=coverup+nexus
I also use an app named Mantano Reader which has an inversion mode for reading at night, i.e white text on a black background.
Lastly I use Screen Dimmer to dim the screen still further when reading at night.
I wouldn’t consider going back to an ereader now – the only advantage one has for me is battery life.