Originally Posted by Andrew H.
The OP is looking for a device to read color PDFs; a full sized tablet is the best choice for that. For reading regular e-books I agree that there are better choices.
Because the OP is looking to read color PDF, an iPad would do very well for that. The aspect ratio of the screen is better for most PDF then a 16:9 aspect ratio. Plus, there is Goodreader
which is an excellent app for handling PDF.