adobe photoshop - Change pixels of a specific color to another color, across all layers?

I am drawing an image that's going to be parsed by a program. It expects very specific pixel colors, in this case black 0x000000FF (full alpha) to work properly.

... I made a whoops! Randomly, some of the pixels that should be pure black are actually 0x000100FF (just green enough to cause a problem). The data is spread across over 200 layers, so fixing this by hand would be heart breakingly tedious.

Is there a way to change pixels with the color 0x000100FF, to the color of 0x000000FF (black) across all layers?

Answer

1. 
   

   Open "Levels" and zoom in as close as you can on one of the incorrect pixels.

   
   



2. 
   

   Using the Black Eye Dropper within the Levels window, click on the bad pixel. It will change all pixels of that color (and darker) to pure black.