When replacing their old ATMs with newer touchscreen models, US bank Wells Fargo hired design firm Pentagram to redesign the on-screen interface. Holger Struppek, who did the visual design on the project, has a highly illustrated story of the design process on his weblog physicalinterface.com.

In the story there's an excellent example of branding versus usability considerations when designing a user interface:

However, blue seemed to be a color that was genuinely pleasant to look at, and even though it was “off-brand”, everyone could live with it. It provided great contrast to the red Return Card button and the yellow alert boxes. During user testing, we presented participants with our color choices and got the same results: “It’s calming”, “I like the blue sky”, ... and so we went with it.

Surprisingly, Wells Fargo recently switched the UI to the current tan color scheme. I don’t know what prompted that decision, but it does bring it back in line with their brand.

[Via: Jane Pyle]