Kdefoldercolor is a script to change the default (often blue) folder icons of KDE icon themes into another color.
Screenshot shows the "lush" icon theme with default green changed to yellow.
More complete documentation is in the script. This is how you use it:
* Download the tar.gz file of the icon theme you want to modify.
* Uncompress it: tar -zxf
* Note to which directory the file was uncompressed.
* Run the script: kdefoldercolor