Professional Technique to Turn a Gray Sky Blue In Photoshop

Picture this: it’s the perfect weather for a walk around the city, you’re in a foreign country, you take a photo of one of its most popular tourist sights with the sky as your background!

But upon viewing the image, you realize the sky is—bland. That is exactly what happened on my recent trip to Milan, Italy.

In this tutorial, I’ll be showing you how you can improve your photo and turn a white/grey sky into a blue sky in Photoshop!

If you have the new Photoshop 2021 or newer then you can also try the new automated method to replacing skies in Photoshop!

Discovering the HSL tab

Right-click on the layer and select Convert to Smart Object.

Doing this will help you preserve the image’s original characteristics despite all of the filters and adjustments that will be applied to the image. At the same time, allowing you to go back to its original content when needed.

Choose Filter > Camera Raw Filter.

Adjust the Tonality and the Color of the image.

On the HSL tab, you can adjust the Hue, Saturation, and Luminance of each color channel—giving you full control of the colors in your image.

With the Blue slider, adjust it to the left and right to bring out more of the blue and make the sky vibrant.

If that doesn’t seem to work and your sky is still grey, you can click Cancel at the bottom of the window to undo the change you applied. Instead, you can create a digital sky.

Creating a Digital Sky

The Select Subject tool works perfectly with inanimate objects or human subjects. However, for photos with intricate details, that may not be the best option. Adobe Sensei can make mistakes sometimes, and correcting it will only cost you time.

For a more straightforward solution, create a selection out of it using the Channels panel.

From there, you will see the Red, Green, and Blue channels that make-up the RGB image. Click on each channel and see which channel has a stronger contrast between the foreground and the background.

In this example, the Blue channel shows exactly what you need. 

Click-and-drag the Blue channel to the New Channel icon to duplicate it.

Whiten the Sky

Next, change the sky into white and transform the rest of the image into black. For this, you can use the Dodge and Burn tools to whiten and blacken the selected pixels. 

Use the Dodge tool to whiten the pixels that are part of the sky.

On the Options bar, select the Range to target Highlights.

For the Exposure, set it to 50%.

Paint over the sky while avoiding the larger areas of the Duomo. It’s okay if your brush grazes over the towers.

If you happen to make a mistake, simply press Ctrl Z (Windows) or Command Z (macOS) to undo the recent step.

On the contrary, use the Burn tool to darken the foreground. 

On the Options bar, select your Range as Shadows and the Exposure set to 50%. Just as you did for the sky, paint over the Duomo with the Burn tool to make the pixels darker.

Next, select the Lasso tool and use it to freehand a selection around the Duomo. 

Set black(#000000) as your Background color, and press Ctrl Backspace (Windows) or Command Delete (macOS) to fill the selection with the background color.

After the selection is filled, you can press Ctrl D (Windows) or Command D (macOS) to deselect.

Enhance the Shadows and Highlights

Next, use a powerful filter on Photoshop where it allows you to take this channel and apply it to itself using a Blending Mode to enhance the shadows or highlights.

Choose Image > Apply Image. 

On the Channel options, select the Blue Copy and set Screen as your Blending Mode, this makes the image brighter and the differences clearer.

Click OK to exit the window.

Next, do the exact same step but for the purpose of making the image darker. Choose Image > Apply Image.

Set the Blending Mode to Linear Burn.

Click OK to exit the window.

Click here to learn more about Blending Modes!

To darken all of the details of the Duomo, keep on repeating this process. You can also use the Brush tool, select a smaller brush, and paint the small details with black color.

Make a Selection of the Bright Pixels

Hold the Ctrl (Windows) or Command (macOS) key and click on the Channel thumbnail to load the bright pixels as a selection.

Click on the RGB to select all channels, go back to the Layers panel and from there, create a Gradient Fill Layer. 

Turn a White/Grey Sky into a Blue Sky in Photoshop

To start selecting the perfect blue sky for your image, simply click on the Gradient Editor.

You can select among the options in the Presets and swap out the colors for your preferred shade of blue.

Feel free to experiment on this part until you find the right color of the sky that fits your image perfectly.

Once you’re happy, click OK to exit the Color Picker and the Gradient Editor window.

On the Gradient Fill window, you can adjust the position of the gradient as well as increase the scale.

Then press OK to apply the changes and exit the window.

Fixing Small Details

If you zoom in on the left part of the image, you’ll see how you may be losing details of the crane because of the applied masks. 

To fix this, select Multiply as your Blending Mode to bring back the details.

Fixing Atmospheric Problems

Create a Curves Adjustment Layer and then right-click to reveal the menu, and select Delete Layer Mask.

Hold the Alt (Windows) or Option (macOS) key while dragging the layer mask to duplicate it onto another layer. 

To invert the effect and apply on the Duomo instead, click on the Layer Mask > click on Invert. Now, when you adjust the curves, it only affects the building.

Another Technique:

To start over, click on the Reset icon at the bottom of the Properties window > right-click on the duplicated layer mask > select Delete Layer Mask.

Select the original layer mask and hold Alt Shift (Window) or Option Shift (macOS) then click-and-drag the layer mask onto another layer to duplicate and invert it at the same time.

Click on the Direct Selection tool so when you hover over the image, you’ll know where the pixels will appear on the curve. 

Drag down a point from the middle of the curve and create another point to bring it back up the highlights to avoid making the building very dark.

On the Layers panel, create a group and name it “Atmosphere.” 

Drag the Curves adjustment layer into the group and collapse it.

Then, hold Alt (Windows) or Option (macOS) and click on the Layer Mask icon to create a black Layer Mask to hide everything in the group. 

Select the Brush tool with white(#ffffff) set as the Foreground color. Then, Brush over parts of the building you want the effect to show.

In the image, selectively paint over the towers on the back of the Duomo to bring out the contrast.

By making this subtle adjustment, the separation between the Duomo and the new color of the sky looks more realistic.

One Last Tip!

Select the Gradient Fill 1 layer > hold Shift > Select the Layer 0 copy > right-click > Convert to Smart Object. This will combine the three layers into one editable Smart Object. 

Next, go to Filter > Camera Raw Filter and adjust the Tonal and Color adjustments.

With the available sliders, feel free to experiment on which adjustments can bring the best out of your image.

On the Detail tab, you can increase the Sharpening to bring out more details but the effect can be so subtle that it’s hard to notice.

To see where the Sharpening is applied, go to the Masking slider and hold the Alt (Windows) or Option (macOS) key while dragging the slider.

The further you adjust the slider to the right, the more it reveals the edges of the image. 

At 90, the sky has completely turned black and it has revealed more details of the building. This also means the sharpness of the building will be applied on the edges of the building and none in the sky.

On the HSL Adjustments, you can adjust the blue slider to make the sky more vibrant and the orange slider to contrast the color of the building to that of the sky.  

On the fx tab, apply a small amount of Grain to get rid of the very smooth, computer-generated look of the image.

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And this is how you turn a white/grey sky into a blue Sky in Photoshop! With this technique, you’ll never have to worry about ruining a great photo of a perfect day!  

I hope you learned a lot in this tutorial and if you found this helpful to save some of your travel photos, be sure to share this on your social media accounts to spread the tips!