Sound and colour
Framestore worked with Walter Greenleaf PhD of Stanford's Virtual Human Interaction Lab to learn about the science behind color hoping to find some concrete conclusions. But instead, he opened our minds to the fact that it's not just as simple as popping up a color and expecting the user to calm down. Reality is much more nuanced than that of course. There are considerations that influence how people perceive color, like cultural backgrounds for example that will taint their perception.
We had to come up with ways to generate color combinations that resonated with our testers as relaxing, using concepts that are similar to how you would compose a piece of music. We picked frequencies on the color wheel with harmonic intervals, so when you look at them they 'sound' visually like a major chord, everything fits and there's no dissonance. And when we change colors, we're actually moving through hue space, as opposed to turning the primary colors up and down. It's a subtle effect, but we feel it really works well. Traveling in hue space is very pleasant.