The white is a pure white, and the tan and grey are very light colors.
The vinyl used in this fence is protected with UV inhibitors to keep the color from yellowing or fading with the sun. The more inhibitor that is used, the lighter the color of the fence. This is why we don't offer other, darker colors.
Click the image to the right for more detail.
There are companies that manufacture paint for PVC fence, but we don't offer any of these products. It should also be noted that painting or altering the finish of the product voids the lifetime warranty.