Color psychology is a topic often brought up when discussing conversion rate optimization. It often comes up as a sort of law of what colors to use, which is based on an article online or some generic description in a book. Color psychology however is far more complex than that and a recent article by Talia Wolf at GetUplift is the best introduction to that complexity I think.
The fact that colors can affect us should come as no surprise to anyone. There are a lot of studies that show that this is true. How they affect us however is still a bit vague and seem less important to a lot of people working with it. This is a big mistake because just like music has an impact on our minds, colors also affect us based on association and everyone has different associations.
Just as Talia brings up the different association differences in her excellent article, like the fact that white is both purity and death, there is also associations based on age and even personal preferences. You also have a whole science behind the different versions and shades of the colors where for example one shade of green can be seen as healthy and full of life and another will associate with pestilence and death.
Talia also briefly touch on the fact that color psychology should not be used alone. It should be considered together with other association factors like typography, iconography and overall tonality. In conversion rate optimization it should also be accompanied by other CRO tools like direction of movement, familiarity and the gestalt laws to direct and highlight the actions we want the users to take.
You will not regret it.