FolderIcon10 allows you to create custom folder icons with or without text added. There's a version for older intel Macs here (which is a 32bit version). There is a newer 64bit version for OS X 10.7 and above (tested up to OS X 10.11 and should work with Mac OS 10.13 plus) here too.
FolderIcon10 is free.
Works with OSX 10.6.8 upwards. Please choose the correct version for your processor (32bit or 64bit). The processor must be an intel one.
If you have any suggestions, please get in touch via email. Many thanks.