
Along with Liverpool, Celtic and others, Real Madrid are notable for usually preferring to wear a change kit when a shorts- or socks-clash arises rather than eroding their classic all-white look.

It has happened in the past – in 1967, Celtic visited Madrid for Alfredo di Stéfano’s testimonial and, with the referee not keen with the amount of white on show with both in default kits, the hosts used the blue shorts from their change kit.
I had thought that, in more modern times, the closest thing we have had to a white-shirt mashup on the pitch from Real was in 2006-07, when goalkeeper Iker Casillas mixed the home top with black away shorts and socks in a game away to Celta Vigo.
However, the following season, for a cup game at Alicante, who were in blue-white-blue, Real wore the navy away shorts with the home shirt and socks (thanks to @rmadyan1 for this information – he also pointed out that the youth team wore a mashup against Lleida in 2015-16).
There were mashups of a sort after the Champions League final wins of 2000 and 2017 – having won the games in black and purple strips respectively, they donned the white home shirts for the presentation. Also in 2017, the league win was celebrated in a white-black-black mix (thanks to Kitman Ramsey for making us aware).
When Real were drawn with Chelsea in this year’s Champions League semi-finals, the expectation was that the English side would wear blue change socks for the first leg in Madrid, but that Zinedine Zidane’s side would then wear an alternative strip, most likely their pink second kit, at Stamford Bridge.
Last week at the Estadio Alfredo Di Stéfano, it was indeed all-white against all-blue as the sides finished 1-1:
However, this morning brought this tweet (kindly flagged for us by Ollie Glanvill):
Essentially, it means that, while Chelsea will be in their usual blue-blue-white, Real will wear their home shirts and shorts with the black socks from their third kit:
An unusual look in the modern era, certainly, but not completely unknown for Los Blancos: