When comparing PyxleOS vs Pixly, the Slant community recommends Pixly for most people. In the question“What are the best pixel art / sprite editors?” Pixly is ranked 14th while PyxleOS is ranked 26th. The most important reason people chose Pixly is:
RGB, CMY, HSB, and a somewhat different HUSL.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Customizable UI
The user interface has support for color themes that are both built-in and user-definable. The canvas transparency tile can also be modified to the user's liking.
Pro Lightweight
The size of the .jar binary is a little less than 1 MB, making the application very lightweight.
Pro Includes a useful text editor
PyxleOS features a basic text editor module that can be used for note-taking or modifying a file that follows encoding standards.
Pro Secure, Java-based cross platform binary
PyxleOS can be used on any OS that runs Java 8 and above.
Pro Free and open source
The download of PyxleOS is free and all source code is available at a public repository at GitHub.

Pro Color selector with different color systems
RGB, CMY, HSB, and a somewhat different HUSL.

Pro Offers color ramp generator
Pixly offers a color ramp generator that then exports directly into a custom palette.

Pro You can use reference images
You can work with a reference image on top of your art, or by its side.

Pro Allows you to continue your work even when not in front of your PC
This tool works on both phones and tablets that run Android, which is handy for when you do not have access to a PC.

Pro Layered projects

Pro Gestures that feel natural on touch screens
In Pixly, you can move the art around with two fingers (like in Google Maps) and change the brush/eraser size with a three-finger pinch.

Pro Supports onion skinning
Onion skinning is also called ghosting. It allows the user to see the past and previous frames, while editing the current frame. This way, the user can make decisions on how to create or change an image.

Pro Mirroring support
In Pixly, the user can make symmetrical art with a mirror, or even go bananas setting up two or more mirrors at different angles at once.

Pro Transparency support
The user can make transparent sprites in Pixly.

Pro Animation support
Even though this is a mobile tool, it's fully featured and even allows you to create animations.

Pro Standard and custom palettes

Pro Live image tiling
The user can create tiles in Pixly and keep an eye on progress in real time.

Pro Color filters
Cons
Con Undo/redo unavailable
Undo/redo functions are not available in PyxleOS.
Con Lacks a number of features
Due to it being relatively new software, PyxleOS is somewhat buggy and underfeatured.

Con No PC version
The PC version has not yet been released.
