I need some photographs touching up

I sell gold cufflinks via the following website:

http://www.burmanmorgan.co.uk

As you can see, the gold products have been photographed at a different time and as such look very different in terms of colour on the products - although they are identical. Ideally, I would like the fox, dog, lion and rhino photographs touched up so they have the same contrast and colour as the pig and elephant so the homepage looks more professional

four photographs to be touched up in total, then saved in the following format

Gold_fox_cufflink
Gold_rhino_cufflink
Gold_dog_cufflink
Gold_lion_cufflink

The alternative is to touch up the pig and elephant to meet the other four - whatever you think would work better.... perhaps even all six, to meet half way.

They must however all look as though they are made of the same material!