Every now and then, an image comes along with complex color schemes that can be daunting to retouch. For such cases, isolating luminosity and color components of the image and tackling each one individually can be helpful.
First, we must define the terms we will be using.
Hue — another word for the specific pigment color, with a scale of a rainbow.
Saturation — the intensity or purity of a hue, with a scale of 100% pure color to grey.
Color — Hue and Saturation combined.
Luminosity — the measurement of brightness, with a scale from white to black.
If you refer to the image below and examine the cube and the lime, you will find that the areas darkened under a shadow to be desaturated whereas the areas facing the light source are significantly more saturated. There is a gradient from saturation to desaturation that correlates with the well lit to shadowed areas, with the exception of catch light which is pure white and therefore desaturated.
If color gels are used in a photo shoot, the difference between a highlight and lowlight color (shadow) can be much more drastic and noticeable.
As a result of excessive Dodging & Burning in the real-world retouching, brightened shadows will often appear desaturated and darkened highlights overly saturated. To fix this problem and to help manage the image, isolating Luminosity from Color and working on the Color first can make things a lot easier. This is usually the point in your workflow after the majority of Dodging and Burning is done.
To better see the area I am working on, I tend to add a temporary Curves Adjustment Layer that I constantly adjust to reveal details that are otherwise more difficult to see. Also, make sure the subject stands out from the foreground as the well-lit areas tend to draw the eye’s attention.
In situations when you need to sample an exact color (Hue and Saturation), creating a Color Map (Ref.1 – see the Color column) will help you get the most accurate results.
To do this, first duplicate your flattened image into a new layer.
Set the Blending Mode of this new layer to Color.
Create a new layer between the original and the Color layer. Fill this new layer with 50% gray (or RGB = 128, 128, 128).
Merge layers “Color”, and “50% Grey” together. The resulting layer is the completed a Color Map of your image, which when you need to extract an exact color, is ready for you to sample from.
If you would just like to view the color map temporarily and don’t need a flattened copy, then simply make a 50% grey layer over your image, and set to luminosity.
Color Corrections In The Real-World Retouching
When the comes time for color corrections to be made, the best way to achieve natural looking results is by painting with a low Opacity Brush on an empty layer set to the Color Blending Mode. I prefer the results from this technique over others because most of the natural color variations are preserved.
First, make a new layer on top of your file and set the layer mode to “Color”.
Next, sample from extreme points in your image’s color range, as sourcing from the image’s natural color pallete achieves better results. Here’s where you could use a Color Map we just talked about above, if you wanted to sample exact colors.
Then select the Paint Brush tool, set its Opacity to 10%, and paint on the empty color layer.
The following GIF file cycles between:
Image 1: Retouched image original colors
Image 2: Color layer adjustments
Image 3: Retouched image after color corrections are applied
Look closely, as the changes are intentionally minor.
Keep in mind that this technique is meant for slight adjustments only, so use carefully!