
Example 1:
Original Image

Dither Applied, proper colors used
What the website says it will appear as

The actual image that results ingame

Example 2 (A more noticeable difference):
What the website says it will appear as

The actual image that results ingame

Side by side view

Like I said before, the images that do look decent have been properly edited and only contain the colors from the allowed pallet.
What I might think be the case here is something to do with the number of fields. These images of course have A LOT, and when you open up the "Paint Sketch" crafting window, this is the result for one of them:

Lots of linseed oil.
Please help us starving artists! We need to express our memes in the way they should be seen! ;_;