Abstract: A slat for a louver comprising an elongated body portion having a longitudinal axis, a front surface and a back surface, and a left edge and a right edge. The front surface has formed therein at least one channel extending substantially the entire length of the body portion parallel to the longitudinal axis, the channel in transverse cross-section being wider at the bottom than the top. The slat further comprises at least one elongated strip having a cross-section at least a portion of which is identical to the at least one channel for removable sliding engagement with the at least one channel. The color of the at least one strip is different from the color of the body portion.