Some color combinations stopped being sponsorship and became art.
When paint became culture
Racing liveries exist to sell something. A sponsor pays to put its colors and name on a car, and in return the car carries that brand around the track in front of millions of people. Most liveries are forgotten the season they appear. A small handful transcend their commercial purpose entirely and become cultural objects, color combinations so tied to great cars and great moments that they outlive the sponsorships that created them. Porsche is responsible for several of them.
Gulf
The most famous is Gulf, the powder blue and marigold orange of the Gulf Oil company. Applied to the Porsche 917 at the end of the 1960s and into the 1970s, the Gulf livery became one of the most recognized color schemes in all of motorsport. The pale blue and the warm orange should not work together, and somehow they are perfect, and on the long, low body of a 917 they became immortal. The Gulf colors are now shorthand for a whole era of sports car racing, reproduced endlessly on everything from modern race cars to watches to clothing, decades after the original sponsorship ended.
Martini
Then there is Martini Racing, the stripes of the Italian drinks company, dark blue and light blue and red running across a white or silver body. Martini backed Porsche through some of its greatest years, and the Martini stripes appeared on Le Mans winners and championship cars through the 1970s. The livery has a particular elegance, the way the thin stripes flow across the bodywork, that makes a Martini Porsche look fast standing still. Like Gulf, the Martini colors have long outlived the original deal and become a permanent part of the visual language of the marque.
Rothmans
And there is Rothmans, the blue and white and red of the tobacco company, which sponsored Porsche's dominant prototypes through the 1980s. The Rothmans 956 and 962 carried that livery to repeated victories, and the clean, bold blue-over-white scheme became the look of Porsche's most dominant endurance era. The tobacco sponsorship is a relic of a different time in motorsport, but the livery itself remains beloved, tied to the cars that owned Le Mans in that decade.
Why they endure
These liveries endure because they are attached to greatness. A color scheme becomes iconic when it rode on cars that won, in eras people remember, in moments that mattered. Gulf is not just blue and orange. It is the 917 and the era it defined. Martini is not just stripes. It is a string of victories across a golden decade. Rothmans is not just blue and white. It is total dominance in the 1980s. The colors are a shortcut to the memory, and the memory is of cars and races that became legend.
That is why these specific combinations still appear everywhere, why people who were not born when the original cars raced still recognize and love them. The livery is the flag of a moment, and the moments were great enough that the flags never came down.