The first pride flag was this 8 stripe rainbow, designed by Gilbert Baker in 1978:

It was intended to be a symbol to celebrate the diversity of the LGBTQ+ community and be representative of queer pride. The main symbol used at the time was the pink triangle, which had been reclaimed from its use by Nazis to be used in activism, first in Germany, but popularised by the American Silence = Death poster. The idea with the rainbow flag was to have something with a more positive background: created by queer people, for queer people. In Gilbert Baker's words "We needed something beautiful, something from us." (Interview with MoMA).

There is quite a lot of hidden symbolism behind the colours. Many different sources say different things about why the symbol of a rainbow was chosen, some of them being: its associations with nature, the Bible story about it, and the hippie movement. Rainbows have been used as symbols throughout history and continue to be used outside of the LGBTQ+ community (the NHS!), so the choice of a rainbow comes with many different connotations, with most of them being positive. The colours also all have individual meanings:

• pink - sex/sexuality
• red - life
• orange - healing
• yellow - sunlight
• green - nature
• turquoise - magic/art
• indigo - serenity
• violet - spirit

I could write an entire essay on Gilbert Baker, but the main points are that he was a 27-year-old war veteran and a drag queen. He didn't have any experience in designing flags but was encouraged by some of his activist friends (notably Harvey Milk). Creating the first two flags took a team of around 30 people, who hand sewed and dyed them at the San Francisco Gay Community Centre. They were first raised on June 25th, 1978, in the United Nations Plaza.

[If you want to learn more about the inspiration behind the first flag, there is quite a lot of information here.]

But how did this 8-stripe version evolve into the 6 stripes that we use today? It was obvious from the start that some of the colours would need to be cut, so that the flags could be produced on a larger scale at a cheaper cost, which was necessary when demand grew after Harvey Milk's assassination. The pink colour was chosen to be dropped due to shortages of pink fabrics/dyes. The turquoise was also removed for the 1979 Pride Parade on Market Street, so that the flag could have an even number of colours and be split in half across the road.

In my opinion, more people should use this flag, because the reasons for its changes are made entirely obsolete by the widespread use of technology (most pride flags are digital, so dyes are irrelevant) and it is a beautiful way to honour the history of pride as well as the intentions behind the creation of the flag.

One of the modern problems with the current rainbow flag is its heavy commercialisation. Rainbow capitalism allows large companies to profit of off LGBTQ+ people, and gain respect for being “inclusive” or “supportive”, without them actually having to help queer people (donating to charities/inclusive workplace policies etc.), and in some cases while actively hurting queer people. Gilbert Baker was entirely against this, especially since many rainbow flags and other pride products are made in unethical working conditions, or in countries which do not has sufficient LGBTQ+ rights. I think that people should be more aware of this problem, and it would be nice if people actively tried to handmake pride items, or support small queer-owned businesses, before turning to give money to corporations who do not really care about queer rights. Modern usage of this flag is largely by people who know the origin (it is generally called the Gilbert Baker flag), so it is often safe to assume they are using it with good intentions.