When you try to save such an image, the background area of the image will no longer be transparent and turns into solid color; in most cases, white i.e. Color 2.

LG Set To Unveil Sliding Doors Using Futuristic Transparent OLED Displays by Nathan Ord — Monday, December 07, 2020, 01:26 PM EDT Comments ...

Although it won’t create an actual transparent image, it will remove the background for sure. Whether it is a solid color or an image in the background, you can use this method to get the job done.