Color has long played a role in US politics.

In 1867, US suffragists Susan B Anthony and Elizabeth Cady Stanton adopted the yellow color of the sunflower – Kansas’s state flower – during their campaign for women’s voting rights in the state. By the 20th century, suffragists added white and purple to their political “uniforms”: white dresses, standing for purity and moral authority, became the most notable marker of the movement.

In more modern times, Black Panthers donned black leather and berets as their aesthetic calling card. Queer Americans have adopted the rainbow as a cheery, powerful sign of diversity. Conservative women adopted pink as a mark of femininity in the 1970s as they fought against the Equal Rights Amendment, which would have changed the US constitution to explicitly ban sex discrimination. Contemporary feminists reclaimed pink through the pussy hat marches of 2017.

In our current political climate, it seems everything is color-coded. Forget nuanced articulations of different positions on the economy, immigration or foreign relations. In the two-party system, it’s either black or white. Or, more to the point, red or blue.

The association of red with Republicans and conservatives, and blue with Democrats and progressives may seem like a permanent feature of our polarized political system. But it’s a pretty new phenomenon in the visual symbolism of American politics.

For most of the country’s history, both parties used the patriotic colors of red, white and blue in their campaigns, without giving any of them particular importance or ideological association. In the 19th century, animals distinguished the Democratic and Republican parties, not colors. The Democrats adopted the donkey, reclaiming Andrew Jackson’s reputation as a “jackass” as a point of pride. Republicans became associated with the elephant after cartoonist Thomas Nast depicted the party as such during the 1870s and 1880s.

If any color identification was made back then, the Democratic party was more likely to be linked with the color red. Mimicking the British color scheme that identified the Labour party with red and the Conservative party with blue, Democrats adopted red to connect to labor movements. By the 1930s, before red became an unfortunate shorthand and slur for communism, the color was an effective nod to the working class, who became an important voter base for the party during Franklin D Roosevelt’s presidency. Republicans, on the other hand, leaned more into blue, evoking the blue Union army uniforms and, by extension, Abraham Lincoln.

Well into the 1980s, wearing red did not connote specific party affiliation. Geraldine Ferraro – the first woman to be nominated as vice-president for the Democratic party – wore a red dress when announcing her nomination. Republican first lady Nancy Reagan was so fond of wearing crimson that her favorite shade was often called “Reagan Red”.

The 2000 election gave red and blue their political associations as we know them today. Using color-coded maps in their election night coverage, TV networks opted that year to mark states that George W Bush won in red and that Al Gore won in blue. And as these maps were broadcast for months as the fate of the presidential election got tangled in the courts, the color affiliation got seared in the minds of voters.

Yet, it was the then-young Illinois state senator Barack Obama who connected this emerging binary to ideology and party identity. In his historic 2004 speech at the Democratic National Convention, which catapulted him into national recognition, Obama blamed “the pundits who like to slice and dice our country into blue states and red states, red states for Republicans and blue states for Democrats”. Identifying religious prayer and small government as “red” values and protection of gay rights and civil liberties as “blue”, Obama argued that you can find both in the US, regardless of the color of the state or the party. “We are one people, all of us pledging allegiance to the stars and stripes. All of us are defending the United States of America,” he said to the roaring crowd.

If Obama hoped for unity that blurred these divisions, the colors’ political association only got more entrenched. By 2010, Republicans decided to capitalize on their affiliation with red to push their political agenda. That year, they embarked on the gerrymandering campaign Redmap, which seized control over state legislatures in advance of the post-census redistricting. While Redmap stood for “redistricting majority project”, the redrawn districts were painted in red, visualizing a Republican takeover.

By the 2012 elections, state colors became more of a cultural designation than an electoral reality. Although Obama carried both Ohio and Iowa that year, Republican victories on the state level made these states reliable “red states”. Or at least, that’s how they are popularly categorized. Some pundits argue that all states are inherently purple, mixing varied electorates and viewpoints. But red and blue reign in our political debates, erasing any nuance in positions or policies.

This color scheme is not just an aesthetic choice or a campaign tactic. This clear division of color impacts not only electoral maps but also the way we think about the other side. Instead of designating policy differences, the colors become stereotypical labels, creating an in-group, out-group mentality that precludes collaboration.

The color binary also offers the illusion that Americans are more divided than ever. Even as we paint Americans’ positions on issues such as abortion, immigration and democracy in broad strokes, there are far more gradations – and sometimes more agreement – in their beliefs than two-color thinking allows.

This flattening is also true when it comes to voting. When we paint states in red or blue, it’s easier to silence minority voices or to ignore the complex political landscape that often defines particular states. We forget that Kamala Harris got almost 5m votes in “red” Texas, and that 43% of the vote in “blue” New York went to Donald Trump. When we divide states into red and blue, we forget that people vote, not land. And those people contain multitudes, not conformity.

The red/blue color framework might be an effective shorthand in creating party identification and clear messaging. But not everyone with a red hat stands for Maga and not every blue-haired person is a liberal. When it comes to politics, it might be better to expand our color palette or at least treat it as a spectrum.