For this photo, I wanted to have one of my small circuit boards on a background that has been changed to be the complementary color of the green parts of the board. When I was setting up the photo I had the circuit board sitting on a black piece of metal. I did this because the metal had enough texture that I made the photo a little more interesting. But also it allowed me to use the quick selection tool on it well. Because the quick select tool is based on color around it an all-black background will be picked up easily making masking very simple in the future. Once I set up that background I put the circuit board on the upper third to follow the rule of thirds. Then I put it into photoshop.
In photoshop I first selected the green color of the circuit board. Then I used color themes to get the exact complementary color of it. This turned out to be a light red. I then made a solid layer with that red color. I then used the quick select color to make a mask over the entire circuit board. Then I changed the layer settings and opacity of the solid layer. I played around with this until I got a red tint on the background on the edge especially. Overall I like this I just wish that I could make the background a bit more red.