Very strange that aseprite counts 180. I checked, and my aseprite counts 180 too, but all other 3 other software I tried all counts 263.. I'll might look into that aseprite issue at some point.

This is one of the tools I used to check, you can see the individual pixels with individual colors here.

Don't worry, we're all learning and all started somewhere :). I just moved your other piece in btw!

As for this one, now the preview image is unscaled, but the main image needs to be unscaled too!

I don't know what is the best way to solve the issue with the tree, but not only does the count read high, also it looks very messy and uncontrolled. We like it best when every pixel has been placed with intention and purpose. Good luck finding a solution or fix!
 

Aseprite tells me it only has 180 colors in it, I used dithering effects on the window to make it look more dark and to add the lighting on the sides (maybe that did the color number increase?) oh and uploaded the unscaled version too. Sorry if the piece looks too weird, I'm just learning to do pixel art 

Hey, the tree seems to be using some kind of effect which bumps up the color count, there are 263 unique ones in your piece! Also, submissions need to be unscaled (at 1x zoom) for the gallery..