Most of the background colors vary significantly from the original colors and the color of the clay is usually whiter than the originals. The Huxfords' book lists the various trademarks that Roseville used. Remember almost every dealer in the country knows what Roseville is, if the price seems too good to be true then it probably is. Know your stuff, don't take anyone's word for it, if YOU are not certain. Buying Roseville online eBay, Yahoo and other online sellers are notorious for selling fakes that are not labeled even when they have been contacted by collectors telling them.
Most fakes now have comparison originals.
All colors are not shown. Most fakes come in 3 different colors and it would be impossible to show each piece in each color. A representative sampling of the colors is shown below. All shapes known to me are listed, however there are new pieces every day it seems. Thanks to all the eBay people who have donated photos to this site.