I've seen this type of question asked before, but I've not seen a satisfactory answer:
I have a specific colour palette, and I can not stray from it at all; I have a specific green (32,144,24) on 93 layers, and I want to change it to a specific blue (24,32,144) on every layer. I have 3 different colours on each layer, and multiple palettes to go through and export (93 layers * 3 colour replacements * X number of palettes = no way I'm doing it manually.)
Because of that, I decided to look for a script to do it for me. I found two such scripts, but they both return errors when running, and do absolutely nothing.
Met with no luck on my own, I decided to ask the internet for help.
Thanks in advance for actually reading the OP and offering any relevant advice.
Two such topics I've viewed that yielded no results:
Replace individual colors in multiple layers
Change the color of multiple layers at once in CS4
As I said in the comments use
Replace Color. True, you'll need to run it for each layer (although you could do it for every layer automatically, keep reading) but it will be much faster than using the fill tool.
Why is that? Well because you can turn replace color into an action. This will require some initial set-up:
loadyour saved files and apply them.
Now you can do this action (and assign it to a keyboard shortcut for speed) and repeat it for every layer.
You can do this for all layers as well but the process will be a bit more drawn out and really is only worth it if you have a lot of layers.
Do as I said above, and create the action. Then go to
File -> Scripts -> Export Layers To Files... and go through that process. Now with each layer being saved out as its own image go to
File -> Automate -> Batch and select your directory of images and the action you created. Run that.
If you're happy with that, you're done! Otherwise, if you want all your images back in one PSD go to Bridge and select your directory of images and go to
Tools -> Photoshop -> Load Files into Photoshop Layers...
Now you should have what you started with more or less but with adjusted colors.
Any other solution would probably have to rely on external scripting, but that is also a worthwhile skill to learn.