When you open a color picker, you will see two or three rows of colors on the left hand side.
SmartSign2Go does not have a built in color picker, but luckily there are quite a few free color picker extensions available for several web browsers that will do the job perfectly, like ColorZilla. Once installed you can pick any color on the web page and the color code will immediatly be saved to your clipboard. This allows you to then paste it into the color code section of the desired SmartSign2Go color palette.