Traditionally, the fencer's uniform is white, and an instructor's uniform is black. This may be due to the occasional pre-electric practice of covering the point of the weapon in dye, soot, or colored chalk in order to make it easier for the referee to determine the placing of the touches. As this is no longer a factor in the electric era, the FIE rules have been relaxed to allow colored uniforms (save black). The guidelines also limit the permitted size and positioning of sponsorship logos.