This is pretty awesome:
A designer, Jamie Divine, had picked out a blue that everyone on his team liked. But a product manager tested a different color with users and found they were more likely to click on the toolbar if it was painted a greener shade.
As trivial as color choices might seem, clicks are a key part of Google’s revenue stream, and anything that enhances clicks means more money. Mr. Divine’s team resisted the greener hue, so Ms. [Marissa] Mayer split the difference by choosing a shade halfway between those of the two camps.
Her decision was diplomatic, but it also amounted to relying on her gut rather than research. Since then, she said, she has asked her team to test the 41 gradations between the competing blues to see which ones consumers might prefer.