I'm having a hard time figuring out what exactly is happening here. At one point, I noticed some of the sprites I was working on were a slightly lighter shade than what was copied from the same document.
The pencil used was 100% opacity. The layers were all 100% opacity. Anti-Alias was disabled. I've ended up with a color index of 80+ while sampling from only 15 or so colors. I can't think of any reason why they'd be changing like this.
In this related example, these silhouettes of copied sprites were left on the background, like they were burned into it. A copy with a pink back is included to show the difference, since it's kinda hard to see. Does anyone have any idea what's causing this? I'm using Photoshop Elements 13.
I'm starting to think it has something to do with the color profiles. Trying to copy and paste between Paint and Photoshop causes a lot of additional colors to appear, regardless of the profile I'm using.