Summary

When an image attachment is added to a Jira issue the image preview of the uploaded file are not always displaying color accurate versions of the original file

Environment

• Tested against Jira 7.13.1 and 8.1.0, but I suspect this affects many more older versions of Jira as well.
• Tested again Chrome and Firefox browsers with same results.

Steps to Reproduce

1. upload a sample image like the one attached  orig.png
2. Use a color picker tool to examine the red color of the displayed thumbnail of that image OR
3. Click on that uploaded file to go into the preview mode, to examine the red color in that preview

Expected Results

Expecting that these previews will display an RGB color value of 255,0,0 for the large red section of that original image

Actual Results

The large red area of those previews is actually RGB value of 252,13,27

Notes

• The original uploaded file can still be downloaded and that download file has the correct colors.
• the thumbnail file created by Jira also has the correct color value for red in this case
• this leads me to believe that the problem is being caused by the way those image attachments (and thumbnails) are being displayed within the issue detail view on the page.
• This problem extends to both the preview itself (when you click on the image in Jira), and the thumbnail as it is displayed in a Jira issue (not the actual thumbnail file stored in the $jirahome/data/attachments/{projectkey}/{issuekey}/thumbs/ directory, just the image displayed on the issue itself.)

Workaround

There currently is no work-around to this behavior of the image preview.