This article is from the Fencing FAQ, by Morgan Burke with numerous contributions by others.
Traditionally, fencing clothing is all white, but the rules have
recently been relaxed to allow "light" colours on the body.
Other colours are permitted on the limbs. The fencer's last name
and country can appear on the back or the trailing leg in block
blue letters; this is required in international competition.
National colours can be worn on an armband on the trailing arm,
or printed on the leg or sleeve. Club or association badges can
be stitched to the upper trailing arm.