Change the colour of objects

Don’t like the colour of something in your photo? There’s no need to put up with offensive hues – here we show you how to change colour and keep the original tone and shading

Swapping colours in objects can often be useful, especially when it comes to simply image improvements such as increasing the intensity of a blue sky, or making grass greener. In addition to these minor cosmetic tweaks, you can also have more fun with the process. Maybe you have an object that you want to see in different colours but need to keep the same camera angle. You only need to use one photograph and put Photoshop to work on simulating the other colours. This technique is used in various different places, from clothes in catalogues to cars, to other merchandise. But it’s not just for commercial use – maybe you have a picture and someone is wearing a garish-coloured t-shirt or maybe you want to repaint your bedroom and want to see how a colour will work without playing around with testers. The Replace Color function is a very useful tool to partly handle this, you can set the hue, saturation and lightness of your colours exactly the way you want them to be. The key to changing a colour successfully is to keep all the shading and tone of the original image, otherwise it will look like you’ve painted colour on (which is probably what you would have done!). Even though the Replace Color function allows you to keep the tone as standard, you should still regularly look back to your original to make sure you haven’t overlooked anything. But just because you’re keeping the original tones and shading doesn’t mean that you have to be completely natural – as our albino strawberry shows! Download the start image here: originaljpg

step 1 – Examine your image
Open up your image, and examine what you have in front of you. Closely look how many colours there are, look at the shading parts and where the light comes in. First of all, duplicate the original layer (PC: Ctrl+J and Mac: Option+J). Name the first one Original and the second one Retouch.

step 2 – Sharpen things up
Every digital photo needs a bit of sharpening, so bring out the Unsharp Mask in the Sharpen filter menu. Set the view to 100% to have an objective look (PC: Ctrl+Alt+0 and Mac: Option+Alt+0). Set the Amount to 80% and leave the Radius to 1.0 px. Click OK.

step 3 – Replace Colour
In the Image>Adjustments menu, select Replace Color. Select inside the panel and all over the image with the eyedropper and add to sample eyedropper tool, to remove all colour. Move the fuzziness bar to 200. Set saturation to -95 and lightness to +75. Don’t forget to save your work once in a while.

step 4 – Red desaturation
Here we will bring back the original background and shadow, green leafs and yellow seeds. Copy your original layer and add an adjustment layer on top of this (go to the black and white circle icon at the bottom of the Layers palette and select Hue/Saturation. The key here is to edit the reds. Select Red from the drop-down menu and move the Saturation bar to -80 and the Hue to +25. This will transform the reds into greys.

step 5 – Yellow seeds selection
Set the blend mode on your original copy to Screen. This gives a bigger contrast between the greys and yellows. Go to Select>Color Range and use the Eyedropper tool to click inside the yellows. Click with the eyedropper tool inside the yellows and then use the Add Sample eyedropper to add the different yellow tones. Set Fuzziness to 85 and click OK. Add a feather selection of 1 px. Set the blend mode back to Normal when finished.

step 6 – Layer Mask
Add a layer mask on this layer, using this selection. You’ll see that this is far from perfect, so we need to adjust manually by adding and removing parts in the mask. First clean up the big parts around the strawberry. For the seeds, use a very soft brush and set the Opacity of the Eraser tool to 25%. Click a couple of times over every seed until the edges will soften and depth will show again.

step 7 – Shades and light
Go with a large soft brush over the edges of the strawberry: erase on the sides to add some shadow again, and paint with the brush tool over the middle. Keep the Opacity to 15% when adding or removing inside the mask. Also bring back the shadow and the green leaf on the background behind the strawberry.

step 8 – Shadow
Add another adjustment layer to your retouch layer. CS2 users can pick out Photo Filter and select Blue from the Filters list. If you have an older version, use a Hue/Saturation adjustment layer to add a bit of blue. The aim is to remove the red reflection shade on the background. In addition we will add a layer mask to bring back to original leaf colour. Fill inside this mask completely with black, and erase only the parts of the shadow on the background.

step 9 – Perfectionism 1
Now, we are starting to have a clear look at what our white strawberry is going to look like. Here we can see that the yellow seeds aren’t blended in enough. Go to your original copy layer and select the mask. Pick the eraser tool and make it larger than the holes around the seeds and click once or twice again to add depth until it feels natural. And with a small brush go around the edges of the seeds.

step 10 – Perfectionism 2
The same problem appears with the leaves, this should be more ‘one entire object’ instead of the leafs on top of the strawberry. Smooth and soften the edges with the Eraser and Brush tool with a small sized brush and low opacity, about 10%.

step 11 – Finish off
Put your original layer on top of the others and show and hide a couple of times. Are there certain areas in the image that are too obvious? Does it look natural enough? Make small adjustments where you feel needed and save your work.