On this video Colin Smith from PhotoshopCAFE demonstrates a really useful and effective technique for making a composite image look much more realistic.
Congratulations, you have just finished working on a complex composite image but the colors of the original image just don’t seem to match the new composited element you added. What should you do? well, fear not Photoshop has a magic tool that can really help you with this problem and it is called (how unsurprising) “match color.
To use it pick your composite layer and go to: image>adjustments>match color. Here you can play with the 3 sliders to get the perfect color match – quite simple.
This doesn’t always work in any picture sadly so you might need to pick a specific color area in your photo and use it as your background for the color match. You might also need to add a curve adjustment layer to help make the math just a little bit better.