Much color work for designers requires avoiding unintentional associations: Red and blue make any map seem partisan, while red and green will always feel a lot like Christmas. But in other design situations, such associations are intentional and helpful.
Colors convey longstanding psychological and cultural ideas, and designers can use that to their benefit. Logo colors might aid in denoting which companies each bar in a bar chart represents, as long as those color differences aren’t too subtle (think Twitter, Tumblr and Facbook blue).
There’s also a reason so many packaged food items come in red packaging (it’s appetizing and comforting) and that food companies often rely on un-dyed tan containers and green imagery to signify healthier... keep reading