How do I change all instances of a color to another in photoshop?

I am have created an image that has elements in it from another image that I didn't have a psd for. The elements in question are black(#000000). How exactly can I change all of these elements to a different color(#292929). I would need for it to basically change all elements that are black in the image to that color. Can anyone help?

I am using Photoshop CS6