Teaching children pink is for girls and blue is for boys is dangerous in the long term

Even if they aren't taught it by their parents (which most children are), from a young age, children in western society are taught that pink is "for girls" and blue is "for boys". If it's not from their parents, it's from toy stores, or clothing, teachers/school or even stationary (and other unnecessarily gendered products!)

In my opinion, gender stereotypes lead to sexism, homophobia, transphobia and hate & discrimination in general. The colour stereotype is one the first social norms we learn, and although not incredibly harmful, it can lead onto more harmful stereotypes. Stereotypes encourage simplistic ways of viewing a complex world. There is a reason humans use stereotypes. They help us make quick decisions in confusing/ chaotic situations, however quick decisions are not always the right ones.

For example, they will go on to being taught that boys and girls wear different clothes, have different length hair, and that boys like girls and that girls like boys. Not many parents teach their parents they can wear whatever colour or style clothes they want, that they can have their hair how they want, and that they can like whoever they want. This then leads on to children being bullied using homophobic slurs (4 years old in the village I live in use the word gay and faggot), which can seriously affect the children who will actually end up gay. Transphobic slurs are part of most young teenager's vocabulary, and feminine words, e.g. "girl" and "pussy", are used in a negative way.

Finally, a lot of stereotypes are superficial, arbitrary and subject to change. For example, 100 years ago, boys played with dolls and lego was unisex. At the moment, we are still clinging onto stereotypes from 50 years ago, and if the youth of today follow them, by the time they have children, the stereotypes will continue in an endless circle.