how to change the border color of sprite object.
If the sprite has a border, you can change it in the animation tab. I made a quick video (no sound) showing how I changed the color of a sprite using the animation tab. https://www.loom.com/share/17e62410a6f2441e94bb73973ef600e0
Not all sprites have borders, though, so if you need to add a border, you may need to do it one pixel at a time or using other editing software before uploading it.
Hope this helps.