This method should work with appropriate modification on any good Photo Graphics program.

Being a landscape photographer by avocation, I have often encountered photos with a small segment of sky that turns out to be totally white or some unacceptable shade of gray. The sky segment is too insignificant to waste the effort of inserting clouds. I like to just make the sky a plain blue sky with just enough variation to make it appear natural. I wrote myself a set of instructions to help me remember every step. The whole sequence only takes four or five minutes once you are comfortable with it. One of the best things is that you won't have to search through mountains of cloud shots to find the perfect one. Blue sky is usually a winner.

  1. Go to the Image tab. Select Adjustments. Then select Photo Filter.
  2. Select the 82 cooling filter.
  3. Copy it to the Swatches section. (Once this is done, the first three steps will never need to be done again.)
  4. select the Set Foreground Color tool (Click it to bring up the Foreground Color Color Picker pop up.)
  5. This automatically will make your cursor into an eyedropper tool.
  6. Click on the cooling filter (blue) swatch that you previously put into the color swatches.
  7. Click on OK.
  8. The foreground color should now be #82 filter blue.
  9. Make sure that the Background Color tool is white.
  10. Use a rectangular selection tool to separate the the sky area from the bulk of the picture. (This is so that the Color Range tool does not accidentally select areas elsewhere in the picture that are similar in color to the sky that you desire to change.
  11. On the Toolbar, click on Select.
  12. Click on Color Range.
  13. Set Fuzziness at around 20. (This varies depending on the complexity of the edge between the foreground and the sky.)
  14. Use the Eyedropper Tools in the Color Range tool to select the sky.
  15. When you have selected all of the sky that you want to change, click OK in the Color Range pop-up.
  16. You will notice that the Color Range selection tool only selected areas that were inside the previously selected rectangular area. The old rectangular selection has disappeared entirely.
  17. Select the Gradient Tool.
  18. Click on the image of the gradient in the Toolbar.
  19. The gradient pop-up will appear.
  20. Select the Foreground to Background gradient.
  21. Click on the top marker over the blue foreground.
  22. Set its Opacity to about 25%. (This is a personal preference. I find that anything much more than 25% opacity looks distinctly artificial. You might want to experiment with this number however.)
  23. Click on OK.
  24. Starting at the top of the sky (where you want the sky to be the most blue) in your photo, click and hold while dragging downward to the point where you want the sky to be white, usually near the bottom edge of the sky in the photo. If you want all of the sky to be blue, drag the cursor down to a point well beyond the bottom edge of the sky. (Use the photo displayed on your monitor as a real time example of what your sky will look like.)

Pat yourself on the back for completing a beautiful looking blue sky.