Green Coffee

Green coffee beans should be of nearly equal size, be similarly shaped, and have a similar color.  This is decisive in knowing how evenly the coffee will roast, so as not to affect appearance or taste of roasted coffee.  Smaller coffee beans will roast differently than larger beans resulting in an uneven cup. 
Uneven coloring hints toward drying problems, whereas uneven shapes indicate a mixing of cultivars. The washed coffee beans should be even and bright.  They should not have uneven or dull color which means they have been dried or processed incorrectly.
Coffee processing is essential for specialty green coffee. If the green coffee beans look faded, the cup quality will be faded. Ensure that green coffee beans have been processed immediately upon harvesting.  If not you will get a fermented cup as coffee begins fermenting immediately upon picking.
If the coffee beans are whitish or faded around the edges, they have been  insufficiently dried or stored in humidity. The cup will be bland and ordinary. The portion of the bean that has a whitish tone has higher moisture than the other parts of the bean.