For all competition matches, the home club has the first choice as to which of
its official kits announced on the entry form it wears for its home matches. The
clubs agree on the colours to be worn from the kits announced on their entry
forms. If the clubs are unable to agree on the colours to be worn by their
teams, they inform the UEFA administration who will take a final decision.
In any case, if the referee notices on the spot that the colours of the two
teams could lead to confusion, he decides on the colours, after consulting the
UEFA match delegate and the UEFA administration. As a rule, in such cases
it is the home team that has to change colours, for practical reasons.