Matching the images which you bring together in a composite is very important. Colour, tone and saturation need to match, otherwise the images look wrong, and look like they have just been plonked together, rather than belonging together in a believable way.
Always match the subject to the background, as the background sets the scene for the lighting, which should also be correct on the subject. (Ref).
Check Layers are temporary layers you can use to match the characteristics of two images, such as colour, saturation and luminosity, so that the two images blend together seamlessly.