Just testing something. Sorry for any inconvenience. 
An issue has been noted at Qiang-Huang’s art blog and also by Debbie Beck Cooper.
It appears Blogger might be (randomly?) auto-adjusting images when they’re uploading, so dark images get lightened/brightened. It’s not hugely noticeable on my image below but while it is marginally brighter than the test file I uploaded, the change is nowhere near as dramatic as the colour-shift Qiang-Huang has experienced.
If this is a new “feature” – of the undocumented kind that Microsoft Windows was infamous for and which Blogger do occasionally impose on users without notice (Lightbox anyone?) – then it poses a massive problem for artists and photographers who do not want their images “corrected”.

For now, however, it looks more like a glitch somewhere in the system.

And indeed, it seems it is both a glitch and an undocumented “feature”.