This is only an issue if the colors of the object(s) in the image exactly match the $secondary color of your theme since that’s used as the background for posts.
I also don’t really think users will actually take the time to edit their images to work on light / dark themes even if this feature were to be introduced.
Are you running into this a lot? If so, your use-case might benefit from some CSS additions to your themes to prevent this from happening. If you share more details about your use-case, like
- what format you use for the images
- some examples of what the images look like
- a link to a page on your site where we can see this issue
then I’ll probably be able to help you with the required CSS.
Do note that when I say CSS, I don’t mean that it will fix each and every image, but it should help with a lot of them.