Using Photoshop's Color Range tool to change a background

This portrait of singer Bev was taken using two basic studio flash heads - one to the left and one to the right, both positioned above her head pointing downwards. The background was a Lastolite style fabric sheet with a neutral grey colour which I now use exclusively because I can easily change the colour digitally. And that's going to be the basis of this tutorial. I will explain how to use the Color Range option and then Adjustment Layers to change the background.

Because I have a plain background it's easy to select the whole lot using the Magic Wand tool, but the difficulty comes when you need the detailed selection around the hair. The Magic Wand will not be any use here and neither will the various Selection tools so we will use the Colour range option.

Go to Select>Color Range to call up the dialogue box displayed on the right. Select the centre eyedropper icon which has a + by it and adds to the selected colours. Click on the background area in the preview window. Certain parts will turn white. When you click on another area it will add to the selection. Select more areas and adjust the Fuzziness setting until all the background area is pure white. Don't worry if some of the area inside the silhouette of the model is also selected we can remove this using the Lasso tool later.

The area where the black meets white is where the selection will appear. When you are happy with this outline click okay and the picture will have the familiar dotted ant selection around the model. Notice how accurate the selection is around the wispy hair but also that some of the finer strands of hair are not selected. Don't worry these won't look bad when we make the colour change.
Using the lasso tool set to minus draw around any areas on the model that should not be selected and these will be removed from the edge selection.

Save this selection - Select>Save Selection and call it "hair".

Go to Layer>New Adjustment Layer>Hue/saturation and tick the Colorize box from the dialogue box. Now when you adjust the sliders you will see the background change colour. Adjusting hue changes the colour, adjusting saturation changes the vividness of colour and adjusting the lightness makes the overall tone lighter or darker

I have selected green using the Hue slider and then reduced the saturation and lightness to make it a bold, but not a glaring colour.

The good thing about Adjustment layers is they don't affect the base picture and can easily be deleted, leaving the picture unaltered or they can be adjusted later to change the settings you've previously made. Here I've gone back and made the background more vibrant and you'll see from the layers palette that I have added a second adjustment layer.

The areas in white in the little boxes are the areas that are affected when you make changes in the adjustment layer. So Hue/Saturation 1 affects the background and Hue/Saturation 2 the model.

To make the new Adjustment layer I first went to Select>Load selection and brought back the "hair" selection that I had saved earlier. I then went to select>inverse (Ctrl+Shift+I). This inverts the selection so when you add an Adjustment layer it's the model that will be affected. I chose Hue/saturation for the Adjustment layer again and played around with the sliders increasing saturation to bring out the skin tones and red in the lips.

When you are happy with the result you can either flatten (Layer>Flatten Image) so the Adjustment layers make permanent changes to the photo, or save as a PSD so that you can come back and make other changes later.

]That's what I've done here changing the background to red and the girl to blue. The selections you make for the adjustment layers can be as local as just the eyes or lips and many colour changes can be made to very specific areas.

You can start using adjustment layers to hand colour black & white photos too.

Have a try with your photos now.