A few weeks back I was bemoaning that the colours were being changed during the upload to Blogger. You can see the difference between the original and the uploaded version below... Google was tweaking the colour balance and contrast in the photos. If I wanted that, I'll do it myself ta very much Google.
After a bit of poking around this evening I've worked out where this is happening. It's not Blogger itself, it's Google+ Images default settings.
To check these settings go to the Apps icon (the 9 small squares) in the top toolbar in your Blogger admin area. Click on More and then on the Photos button. You'll then see your photo stream.
To the top right of your stream, click on the down arrow next to Share. Down near the bottom, go down to the Apply Auto-Enhance and select Off.
Hopefully this is of use to some of you