Inconsistent folder cover colors on PB Inkpad Color 3.

[fengduoyin]

Hi!

There's a thing that currently bothers me in KOReader and I'm trying to find a way to work around it, so let's me preface it by describing the behavior I'm dealing with.

I have Project Title installed, which includes folders being able to show covers out of the box. I've noticed that when I just exist any folder that has books in it, covers look vivid at first, just like epub files usually do. Then, if I go through library, covers start looking washed out (I've included photos of the same page for visualization).

Now here's 2 things I noticed:

1. While I first discovered this behavior in PT, I've confirmed that the same happens in CoverBrowser with folder covers patch, meaning it's KOReader's innate behavior, not a PT issue.
   
2. Folders never look washed out if the page of the library that is being displayed has any epub files alongside with them.

My backend hunch makes me think that, because CoverBrowser doesn't show folder covers out of the box, there's likely a condition that checks for epub files on the page, and only applies saturation filters if there are any. Interestingly, that condition doesn't clock that there aren't any epubs to be displayed when you first exit a folder into a page full of folders, and that's probably why covers initially look vivid.

Now, the issue is that I don't really know how KOReader works on the inside, so I'm not sure how to proceed further (lua not being the coding language I know doesn't help either, although I can somewhat understand the code).

Hence why I'm here. If anyone knows which modules apply saturation filters and at what point, I'd be very grateful if you'd able to pinpoint them, because I'd like to try making a patch that fixes that behavior into one where filter is applied at all times.