I don't think the HD 8 actually has a blue filter. It looks like an orange to red filter overtop of the display. It turns anything black to the color level you choose. The screenshots from Play Books looks like it filters out blue instead of a filter over top of everything - the font stays black. If you use the blue filter on the Fire HD 8 with the screen background set to black it looks really bad. Play books only changes the color of the white text, not the background. Here's screenshots from the HD 8 and Play books on my Tab S both using a black background as the starting point:
