The concept of "Christmas Beers' is well known in Belgium. In the Netherlands and Germany one rather speaks bokbieren, although the latter are especially popular in the fall. Because specialty beers at Christmas anyway have been very popular, many Belgian breweries do put a special brew in the market. That way, you can enjoy extra for the Christmas period.
Most winter and Christmas beers are dark in nature, but do not be mistaken. Also blonde counterparts are certainly popular, and even called gluhkrieken (Liefmans). And of course the brews aged in oak barrels with even numbered bottles are ideal Christmas gifts.