.PSD preview using CMYK does not render

Summary

Per Display Files and Images, .psd preview is supported, and doesn't specify if the file needs to be saved as RGB or CMYK.

• When saving the .psd file as RGB, image previews normally. This is expected as RGB is meant for images on the web.
• When saving the .psd file as CMYK, the image does not preview, and instead shows this:
  

Environment

Confluence Server (tested with 6.7.0 and confirmed by customer with 6.4.0)

Steps to Reproduce

1. Create two separate .psd files in Photoshop, save one as RGB and one as CMYK
2. Attach both to a page in Confluence and test the preview.

Expected Results

Both images should preview as Confluence is expected to support preview of .psd files.

Actual Results

The CMYK image will not preview.

Workaround

Workaround is to save the image as RGB.