Step 17: Add A Stroke To One Of The Sections

If you look in the Layers palette, you'll see that you most likely have the Hue/Saturation adjustment layer at the top of the Layers palette ("Hue/Saturation 4") selected, since it's the last one you added (the currently selected layer is highlighted in blue). Click on it to select it if it's not selected. This adjustment layer controls the color of the section on the far right of the image. We're going to add a black stroke around this section. Click on the Layer Styles icon at the bottom of the Layers palette and select Stroke from the bottom of the list of layer styles that appears:

This brings up the Layer Style dialog box set to the Stroke options in the middle column. First, lower the Size of the stroke down to 1 px, then set the Position of the stroke to Inside. Finally, click on the color swatch at the bottom of the options, which brings up Photoshop's Color Picker, and select black as the stroke color, then click OK to close out of the Color Picker:

When you're done changing the options, click OK to exit out of the Layer Style dialog box. If we look at our image, we can see that we now have a thin black stroke around the section on the far right:

Step 18: Copy The Stroke Layer Style

Now that we've added the stroke around one of the sections, we can simply copy the layer style and quickly paste it onto the other three sections! Go up to the Layer menu at the top of the screen, choose Layer Style, and then choose Copy Layer Style:

Step 19: Select The Other Three Hue/Saturation Adjustment Layers

Click on the third Hue/Saturation adjustment layer in the Layers palette (the one directly below the top one) to select it, then hold down your Shift key and click on the first Hue/Saturation adjustment layer (the one directly above the Background layer). This will select all three remaining adjustment layers at once. You'll see all three of them highlighted in blue:

Step 20: Paste The Stroke Onto The Adjustment Layers

With all three remaining adjustment layers selected, go back up to the Layer menu at the top of the screen, choose Layer Style once again, and this time, select Paste Layer Style:

And just like that, the stroke is now applied to all four sections, separating them from each other a bit better:

And with that, our main photo effect is complete! Let's finish things off by looking at an easy way to change all four colors at once, as well as how to brighten up the colors if needed. We'll do that next!