Silver Bengal Facts

Silver is not actually a separate colour. Silver is the effect resulting from the Inhibitor gene (I). The Inhibitor gene when  present suppresses  the yellow pigment production.  The silver gene is a dominant gene.  If you don't see it then it is not there, it cannot be carried.  If you get a brown kitten from 2 silver parents, that kitten can never produce silver (unless it is mated to a silver), and the silver gene will never show itself in future generations.

Genetics
The letter that designates silver is "I" for the Inhibitor gene, and the letter "i" is for non silver.  You cannot tell an II (homozygous) silver from an Ii (heterozygous) silver by looking at the cat.  You can always tell an "i" is NOT silver, and that there is no "I" in the cat's genetic makeup that would produce silver later. 
Therefore an Ii x Ii silver will on average produce 75% silver (1 homozygous and 2 heterozygous) and one brown kitten.
A homozygous II silver regardless of what it was mated to would produce all silver kittens;-
II (homozygous) x Ii (heterozygous) would produce all silver kittens (2 homozygous and 2 heterozygous).

If you mate Ii heterozygous with a brown you get Ii x ii= 2 heterozygous silvers and 2 ii Browns.
(All the above are of course averages).

Further facts 
Breeding 'good' silvers is going to be the biggest challenge yet to Bengal breeders.  There is no point in rushing in to buy the first silvers you see if they are tarnished as it is going to be difficult to breed it out.  Even putting silver to silver can produce tarnished kittens. Silver to brown matings are likely to produce many more tarnished kittens if one of the parents is highly rufous in colour, brown Bengals with light backgrounds and/or little background colour are preferable to use with the silvers, if you are not doing silver to silver matings.
Good Silver Bengals should resemble the Snow Leopard in background colour with black or charcoal spots/rosettes with a non domestic head and very little or no tarnishing.

GCCF
Up until mid 2005 the main UK cat registering body the GCCF said they would not recognise Silver Bengals., however it now seems they have changed their minds and are going to accept them.  Silver breeders in the UK have had to register with other registering bodies like TICA and Fife up until now to obtain championship titles.  These alternative registering bodies are quite small in the UK compared with the GCCF.  The GCCF through its registration policy will show if there is 'silver' in the lines.

Concerns of some UK breeders

There are some Bengal breeders who want the browns out of silvers only to be used with silvers, and don't want silver mixing with the brown lines, this is because they are worried that the 'broadband gene' may lift the spotting nearer to the end of the hair shaft with each successive generation of silver to silver matings, (silver breeders will have to breed back to browns every so often to reinforce spotting).  Some breeders of brown Bengals are also worried that 'type' could be lost, and 'solid colours' and 'smokes' will get into the breed through the outcrosses used.
 

Outcrosses
In the USA both the Mau and the Ocicat have also been used as outcrosses.  One of the arguments against these two outcrosses in the UK is that both cats are ticked, the Mau also has very small spots.   Whereas the American Shorthair (ASH) and British Shorthair will eliminate ticking difficulties. A good ASH is extremely clear coated, with excellent contrast and clarity. This breed more than any other has been developed for high contrast silver.

Benefits of Silvers in brown lines.
The broadband silver gene has been shown to clear ticked coats, this would be an advantage for those breeders who still have some ticking in their lines.

  As the silver gene cannot be carried it will not 'pop' up in later brown generations, unless the Bengal is mated to a silver. Many USA breeders are choosing to put their silvers to browns to obtain beautifully clear coats.  There have been some stunning pictures of brown Bengals out of silvers in the USA.  Any brown Bengal with silver in their lines in the UK registered with the GCCF would be over stamped ad-infinitum, so that breeders who did not want them in their lines could avoid them.  There is controversy about this in the UK.