It's important to remember to save it as .PNG as some of the other artists pointed out!

Take the criticism with a grain of salt, and don't let it get under your skin. However, let it get under your mind, and help you improve your foundations in pixel art.

ya i know. but i use to just save it as a gif or something so it loads on graal editor better and auto shows when u close it and reopen it. if you do it as a .png u have to load it to the graal editor every time u open it so i just thought it was easier just to do it in gif

you can save it in gif, gif normally is fine i believe, but don't save as .gif in paint, paint messes up colors in .gif, and .png costs less space then .gif, although i don't think that's much of a deal.

You need to save it as an 8-bit PNG for it to show up in the level editor.
It's probably best to avoid GIF at all costs since you gain no benefit from it, and it will only hurt you in the long run. PNGs aren't hard to export/save/optimize once you learn how.