adobe photoshop - Change the color of multiple layers at once in CS4

I apologize if this question has been answered already, I'm not experienced with Photoshop and not sure what to search for. I'm using CS4. I have a grid made up of different layers, basically like a checkers or chess board, where each square is a different layer. I've decided to change the color of some of the squares. I'm trying to find the best way to do this.

It seems I can do this by setting tolerance to 0 on Paint Bucket, since my squares are monocolor. However, in the future they might not be. Is there another way to do this, besides selecting exactly the right pixels first?

I saw a suggestion that I can "lock" the layer pixels so that transparent pixels aren't overwritten. However, the options are not available in my Photoshop version.

Answer

Photoshop is vast so there are 12,000 ways to do everything, but here's what I would suggest:

If you are going to change the colors more than once, merge the layers of the same colored checker squares.

1. In the Layers panel, click the first checker layer


2. Ctrl + click each additional layer of the same color


3. Right-click and select Merge Layers


4. Select the newly created layer



5. In your Layers panel, next to the word "Lock:" there is a transparent square icon called Lock Transparent Pixels click that. See the image below You should have this because I'm using CS3 and its there.


6. With this selected, you can now change the color of your squares without losing transparency.


7. Repeat as needed for checker layers for the other color