We have the problem, that one image in the catalog is shown negatively in Magento below the gallery:

I tried to reproduce with n98-magerun2 dev:console

$i = $di->create('\Magento\Framework\Image',
  ['fileName' => 'original.jpg']);
$i->open();
$i->resize(90,90);
$i->save('small-repro.jpg');

Which I cant.

While I can reproduce it by

rm product/cache/.... $ rm small.jpg 

and reloading the category page -> it's shown wrong again.

The image also shoes like this when downloading or showing in different browsers, so it seems to be a problem within the server / Magento.

1. Did anybody see this before?
2. How can I dig deeper into it?