Superman’s blue, red, and yellow costume might just be the most iconic superhero outfit of all time, and for many people, the suit that Christopher Reeve wore in the 1978 film is the definitive version. The person responsible for that memorable look, Academy Award-winning costume designer Yvonne Blake, died on Tuesday. She was 78 years old.

Blake, who was born in Manchester and died in Madrid several months after suffering a stroke in January, was a prolific and acclaimed costume designer. She got her start working for Hammer Film Productions, a famed British studio best known for gothic horror films, but soon rose up the ranks to become a full costume designer, according to Variety. She won her first Oscar at 31 for her work on 1972’s Nicholas and Alexander. Some of her other credits include Jesus Christ Superstar, The Three Musketeers, and The Four Musketeers, the last of which won her another Oscar.

The Reeve Superman costume is no doubt her most enduring contribution to pop culture. Here’s how pBlake’s initial notes](http://www.sciencefictionarchives.com/en/collections/346/superman-costume-original-sketch-by-costume-designer-yvonne-blake), written before Reeve was even cast, described the costume:

Leotard in shimmering blue two-way stretch fabric worn over fake muscles and harness for flying. Capes to be made in various flowing fashion for resting. Boots in glove leather or elastic with small heel. ‘S’ motif in red and gold on breast and again in all gold on back of cape. Gold metal belt with ‘S’ buckle.

Compared to later film iterations of the Superman suit, Blake’s original version has a classic simplicity that feels more wholesome than the grittier, textured costumes seen in films like Justice League. Whereas the current DCEU Superman is dressed in chainmail-like dark blues and reds and doesn’t have those classic red trunks, the version Reeve wore is bright and bold. It feels like clothing, rather than armor. Which, when you think about it, makes sense. Why does the man of steel need armor?

The Hollywood Reporter notes that it took a lot of work to find exactly the right shade of turquoise for the costume, because if it was the wrong shade it would’ve disappeared into the green screens and blue screens used for filming flying scenes.

“If the lycra was either too green or too blue Superman would disappear and all we would see are his shorts, his boots and his cape,” Blake’s quoted as saying.