The satem languages merged the labiovelars with the plain velar series , while the palatovelars became sibilant fricatives or affricates of various types, depending on the individual language. In some phonological conditions, depalatalization occurred, yielding what appears to be a centum reflex in a satem language. For example, in Balto-Slavic and Albanian, palatovelars were depalatalized before resonants unless the latter were followed by a front vowel. The reflexes of the labiovelars are generally indistinguishable from those of the plain velars in satem languages, but there are some words where the lost labialization has left a trace, such as by u-coloring the following vowel.