Atlético Madrid have agreed with UEFA to play in their black and yellow away kit in tonight's Champions League semi-final first leg at Real Madrid (20:45 CEST).
Atleti have worn their red-and-white home colours in each of the sides' European clashes in the last three years: the 2014 and 2016 finals, and the 2014/15 last eight.
Atlético to wear black out of superstition?
Having been knocked out by their city rivals in all three ties, there are suggestions that the step has been taken by Los Rojiblancos for reasons of superstition.
However, the decision is understood to be down to a desire on the part of Europe's governing body to avoid any possible clashes with Real's all-white home kit.