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.

If you save an image that has a transparent background as a JPEG, it will automatically get a white background in the output. To keep the image with the background transparent, you will need to ...

More specifically, I typically need to convert an image with a white background to have a transparent background so that it blends more naturally with a non-white background.