We looked at a good number of existing color pickers in different systems. From Hue, Saturation and Lighting circles to the Mac crayons, all had advantages and disadvantages. The HSL circles provide a great range of colors, but it is hard to select the same color twice, plus, not all people understand it well. Other pickers were not too suited for the iPhone/iPod touch interface.
We finally decided to evolve our current color picker, adding more colors, for a total of 24, getting rid of the text and giving it a different aspect:
After several tries, this was the final result:
We hope you like it!