Importing an image allows you sample a wide gamut of colors, and can therefore help you create a color-palette. What if you could simply load an already succesful palette, something that doesn't require any effort on your part. I've done exactly that.
First let me introduce my inspiration. Odosketch is a popular online interactive sketchbook. It is simple yet elegant, putting a simulated-brush in the hands of its members. Although, its major highlight is it's limited soft-pastel color-palette. It's wonderful. If you google-image-search, "ododsketch" you'll see this palette in all of its drawings.
So I thought, what if I could steal their rainbow and bring it back into the Sketchport.
So here it is.
Now you can use this too. I've included a template for anyone that wants to try it out: http://www.sketchport.com/drawing/1080040/odo-palette-template/download