Colour boost Action
This tutorial offers an alternative to the saturation option when you wish to dramatically boost the colours in an image. We will make a photoshop action for this colour boosting technique so that it can be applied easily to any image in the future.
The first step is to create a folder for your action. You can call it what you want, I have called it ‘ColourBoost’.
Give the first step a logical name and start recording.
Photoshop LAB mode
Convert your image to LAB mode. LAB means there are three channels L=lightness and two colour channels A and B.
The next step is to duplicate the layer by dragging the image to the ‘Create new layer’ button on the layers pallet or by choosing to duplicate the layer under the ‘Layers’ menu. More information about working with layers here and here.
Tone Curve adjustment
Now we are going to adjust the curves on the duplicate layer.
First choose the ‘a’ channel. Grab the line in the top corner and drag it to the left. There should be no curve in the line. Make a note of the value. Now do the same for the bottom corner and be sure to use exactly the same value as you did for the top corner. What you are doing is tightening the levels of the ‘a’ colour channel. Keeping the same values will ensure that you are not introducing an un-natural colour cast. The line should cross the centre.
Now do the same for the ‘b’ channel.
On the ‘lightness’ channel, you can give the line a slight curve to increase the contrast slightly. See here for help with curve adjustments.
By selecting and deselecting the ‘preview’ button, you should be able to see the effect of the curve adjustment.
The last stage is to convert the image back to RGB. You will see a dialogoue box asking if you want to flatten the image. Choose ”Don’t flatten’ because you might want to make adjustments to the layer first. For example you might want to create a mask and apply the effect only to certain parts of the image. Or you might want to use a different style of over-lay such as ‘multiply’ or ‘screen’.
Stop recording the action!!
Lets look at my image before and after the colour boost.