Why are all my images, on http://www.theswordshop.co.uk coming out much darker in the front end than they are in the back end?

I'm on Magento 1.7.0.2

My images are all JPEG, 72dpi, dimensions of 650px x 650px, RGB and 8bits.

Here's an example of what my images look in the backend compared to the front end:

*Image in correct colours (as seen in the backend)*
![Backend][1]

*Image desaturated (as is in the frontend*
![Frontend][2]

  [1]: https://i.sstatic.net/CTCow.jpg
  [2]: https://i.sstatic.net/zc1iC.jpg