The psychology of colour can be a difficult one to comprehend. It is a complex subject that taps into our subconscious psyche. Certain colours can make us come to preconceptions about images without us even knowing. Particular colours can help convey certain moods. Red could be linked with passion or anger, yellow linked with happiness and creativity. Some things are synonymous with being associated with certain colours. Like green grass or blue sky. So as you can imagine colour has a massive influence over a picture.
When colour photos were introduced after many, many years of monochromatic images they were looked at negatively by photographers who saw photos as an art form. They felt it cheapened the art form, as it was just capturing what you saw rather than being creative with light and shade. In fact, if anything it was adding another element into images. Now you were having to think about how colours interact with one another. Black and white photo enthusiasts did not see it that way, but we don't see the world in black and white. These days the photos that we share don't even have to show the colours that we see around us and more often than not don't. Maybe the photographer wanted to make us feel something other than what the real world situation provided. Maybe changing the colour enhanced the picture significantly. Maybe it was just for artistic flair.
So how do you change the colours in a photo? Well using photoshop there are loads of ways to change the colour of something. Here I will show some of the ways that it can be done by changing some purple grapes red.
Hue/Saturation Layer
This is probably the one that most people go to. You are literally selecting the specific colour that you want you change and seeing the colour it will be visually. So it is easy to use as accurate as you make it and produces some of the better results.
At the top navigation bar click Layer>New Adjustment Layer>Hue/Saturation.
It will look like above image.
The Hue slider changes the colour, the Saturation changes the colour intensity and the Lightness changes how light or dark the colours are. The bottom rainbow bars are the visual of what the before (top) and after (bottom) will look like. Also it show the thresholds.
There two important parts to this; the drop down menu which says master; the eyedropper tool.
Master changes all the colours at once. Click the drop down menu and you have different colours available to isolate and change. For this I chose blues as i'm changing the grape colour. The eyedropper tool refines the selection of that colour. Click on the left of the three eyedroppers and click on the colour in your picture you want to change. Slide the Hue slider to change the colour.
These are the settings I needed for my photo. As you can see from the bottom bars the white marker show what range of colours have been selected, which is blues and purples. The bottom of the two bar show what the colour have been changed to, which are primarily red.
Colour Balance Layer
This one was a little trickier to get right. So it may not be the most preferable way to change the colour of something in Photoshop but it works none the least.
Click Layer>New Adjustment Layer>Colour Balance
This one works with only Shadows, Midtones, Highlights. So you can't isolate a certain colour to change rather than a range of luminance tone. It will change colours that you don't necessarily want to change so you will have to use the layer mask that automatically gets applied to the layer to remove the effect from where you don't want it like the vine and the leaves from this photo. Make sure that you have 'preserve luminosity' checked as it is below so it doesn't make the image darker or lighter when changing the colours.
When you do get the balance right it does leave quite a nice end result. It is just a bit more difficult than doing it with other methods.
Selective Colour Layer
Selective colour works slightly similar to Hue/Saturation in the fact that you isolate certain colours to change. You don't have as much control over it as you do with Hue/Saturation but the upside with this is you have whites, midtones and blacks to adjust as well.
Click Layer>New Adjustment Layer>Selective Colour
It will initially look like this below
For this image I chose the blues from the drop down colours menu. Selective colours works rather off the CMYK colour scale instead of RGB. So you must know the opposite of CMY is RGB in the order. By removing cyan more red appears remove magenta, green appears finally remove yellow and get more blue.
Even though the blue drop down did most of the heavy lifting I also had to adjust the Magenta, Grey, Blacks and Whites slightly to get the colour similar to what I had done to the others.
This is the result that I got using this method. It is a good way to change the colours you want.
Brush + layer blend mode to hue
If you are a natural painter or drawer then this might be a prefered way for yourself as it is just colouring in within the lines.
First you will need to create a new blank layer. (see below)
On that blank layer you can now paint with whatever colour you want to paint with. for this I will elect whatever shade of red I want and just paint over the areas which have purple grapes like below.
Clearly this does not look like red grapes, it is just block colour. The final step is to change the blend mode of the layer from Normal to Hue. This will transpose the colour that you have painted but keep the luminosity of the original image underneath.
Replace colour adjustment
I really like this method as it is very visual you can see exactly what you are going to be changing and the results of your changes in real time. It just has one massive flaw to it. It is a destructive way of editing. You can't change it when you have done it other than doing it again.
So firstly make a copy of whatever you want to change the colour of and use the copy. If it goes wrong you always have the original as a backup.
Select the backup layer and click at the top bar Image>Adjustments>Replace Colour.
The pop up box you get looks like the image below. Three eyedropper tools at the top, first to select the colour that you want to change, second to add to your selection, third to remove from your selection. Fuzziness is like accuracy of colour, lower fuzziness mean your selecting that colour specifically higher fuzziness means your selection area gets bigger and bleeds into similar colour variances. The harsh black and white image shows you exactly what is selected. White is what is selected and black is what isn't. Down the bottom are the sliders to change hue, saturation and lightness. Behind this box is your actual image and this will change as you change the hue, saturation and lightness sliders. So you can see exactly what is changing and what the final result will look like.
I would probably use this method as my prefered method if it was a non destructive method of editing. Unfortunately this method doesn't work on Smart Objects even that would make it a viable option to use. But for me this is a major factor of me not using. If you can get past that and don't mind working destructively then it is a nice method.
My pick of the lot is the good old trusty Hue/Saturation layer.
So now you know how a few different ways to make the world around you the colours that you want it to look. If you want to make your tell a different story or deliver more of a statement now you can. If you want to go against the grain and have blue grass and green sky then do it.
That is it for now, thanks for reading and see you again soon.