It does indeed look like the solution you want would involved scripting.
I took a look at this guide for you:
The top of page 9 explicitly states you can save files.
What you'd want to do is create a script in one of the supported languages (page 9 of that document).
The script should do the following:
1) Open file A
2) Run loop that calls a method (function or subroutine, all names for same thing) that does the alteration you desire (such as modify hue by 2%) and increments the file name by one letter each run through the loop. (I would suggest numbers, especially if you are doing more than 26, but that's your call). End the loop.
You said "I need to be able to edit and hopefully create the Applet/Action myself."
Here's a couple free resources to learn if you wish:
I'm a professional software dev, and my wife decided to switch from teaching to software last year and used the codeacademy website to get started and then went to a software bootcamp, she said it was a good resource for learning.
(If you already know how to program, you may just want to skip to this and take a look. If you feel overwhelmed, backup and check out the first resources I sent and then look at this page again and it will seem to make more sense).
I hope that answers your question.
If I've answered your question, I would appreciate it greatly if you would rate me.
Else, please let me know what further assistance you need.