The only way to do this with pure CSS would be to overlay the thumbnail image with a translucent image of the appropriate tint using position:absolute and z-index with something like:
<p style="position:relative; z-index:1; width:120px; height:120px;">
<img src="thumbnail.jpg" style="position:absolute; top:0; left:0; z-index:1;">
<a href="destination.html"><img src="tint.png" style="position:absolute; top:0; left:0; z-index:2;"></a>
You'd have to adjust the width and height settings to match your thumbnails, and it might be cumbersome, but it would work.
If you can do some PHP programming, it would be simpler to create a script that would tint the thumbnail image as needed. There's a sample script in the comments section at http://php.net/manual/en/function.imagecolorallocate.php that you could use as a basis for such a script. Good luck!