During the opening ceremony's parade of nations, many athletes wore gloves with multicolored fingers, including the entire Greek Olympic team.
Some people watching the ceremony incorrectly assumed that the athletes were wearing rainbow gloves as a sign of LGBT pride in opposition to Russia's discriminatory laws.
Actually, the multicolored accessories are the official gloves of the Sochi Winter Olympics.
The colors on the gloves' fingers represent the five colors of the Olympic rings. (The colors of the rainbow are red, orange, yellow, green, blue, indigo and violet.)
The gloves are part of the official merchandise and are available for sale all over Sochi.
Basically, if there's no purple and one of the colors is black, it's not meant to represent a rainbow.