Have you ever taken a picture and found it was a brilliant except the dull and boring background. Well this tutorial will show you how to change the background to a more exciting and vibrant colour while all other aspects of the picture remain untouched. Many of the techniques I will be using in this tutorial are from the genius Bert Monroy from Pixel Perfect. This technique works brilliantly on pictures that are not littered with various amounts of different colours in the sky. For the more colour complex pictures it requires just that little bit more tweaking to get perfect. If you want some of the pictures I used in this tutorial there are thousands over at Interfacelift.

Step 1

First open your image and go to the channels, in here click through the red green and blue channels to find the channel which has the most contrasting colours, in my image it is the blue channel where there is dark blacks and light whites. Now duplicate this channel by right clicking on the blue channel and duplicating, this creates a new channel called blue copy

Step 2

While still remaining on the blue copy channel you duplicated go to image -> adjustments -> curves

A curves dialogue box should appear. If you go outside the curves dialogue box you can see that an eye dropper appears, click around the black parts in the image and you can see all the colours correspond to a certain position on the curves grid. Now we will force all these colors to even more black. Do this by holding down and clicking in the curves graph on the far bottom left area, if you don’t get it right first time simply press cancel and you can do it again. Just make sure that no other colors in the image except the darks are changing. When your happy with the result click ok.

Step 3

Go back to your channels and click on the RGB channel then drag the blue copy channel into the “Load channel as a selection button” underneath. This should now select just the areas we need to change and the red area on the image will be protected by the layer mask.

Step 4

Make sure you are in the RGB channel and in the actual images layer and add your desired gradeint to the image to change the colour of the sky. Here is my final image below which I applied a whacky orange and yellow colour to.