Preview background removal issue - faded color

An alternative to background removal in Preview is selecting the donor image in the Finder, right-clicking on it, and from the Quick Actions menu choosing Remove Background. Compare that result to those of Preview.

If you overlapped that original image in Preview during the background removal process, it may have stripped the brightest whites from the original image causing the dimmer result.

Seems okay here.

I can't replicate your issue.

In Pages, make sure the Opacity for the image is set to 100%:

MtD

As a test, download this PNG and see if the problem persists:

MtD

Try converting the cutout .png to a jpeg via the finder.

That will add a white background behind the cutout.

Try uploading that jpeg and test.

MtD

Would it be possible to share the original image file (before you removed the background)?

Perhaps it's the website?

No idea.

MtD