Color Isolation
This tutorial will teach you out to get one color to stand out in a black and white photo. We’ll be using the hue/saturation tool to isolate one color in a photo using Photoshop.1. Select a random photograph that you want to use. I will be using the following:

2. Create a new adjustment layer under Layer > New Adjustment Layer. Select Hue/Saturation.
3. A window will come up with the Hue/Saturation adjustment options. There will be a drop down menu with the different colours that you can select and change the settings for.
4. You should set the saturation to -100 for everything apart from the Master channel and the colours that you want visible. In my case, I will be setting all the colours to -100 apart from the Master channel and green - as I want green to be my subjective colour, the rest isolated.
5. Now here’s my image with only the green visible. The rest of the colours are in black and white. This is a technique that is effective in distinguishing a subject that you wish to focus on.