A children’s clothing company which revolutionised gender-neutral clothing for girls has turned their attention to boys, launching a crowdfunding campaign on Tuesday that reached 50% of its funding aim in the first hour.

Frustrated that they couldn’t find shirts for their five sons with unicorns on them or bright colours, animals, sparkles and rainbows, Eva St Clair and Rebecca Melsky decided to make them themselves.

“Gender stereotypes work both ways,” said St Clair. “Things that have been deemed ‘for girls’ do not appear on boys’ clothing anywhere and that limits what all kids can be and do.

“My son always tells people his favourite colour is ‘rainbow’. But shirts with rainbows or even just bright colours are only in the girls’ section,” she added. “As a parent, I think it’s important for his development to encourage him to embrace what he loves rather than force him into a narrow definition of masculinity.”

The new clothing line will offer boys’ clothes with motifs and colours usually found only on girls’ clothes: ice-cream sweatshirts, sparkly unicorn shirts and brightly coloured winter coats.

Parents have already reacted with enthusiasm: their crowdfunding campaign set a goal of $20,000 (£15,200) to bring seven Boy, Wonder products to market. An hour after it launched, more than $10,000 had been pledged.

Eva St Clair, left, and Rebecca Melsky. Photograph: Zach Gibson/AP

A survey by St Clair and Melsky found that “parents want clothing that helps communicate to their sons that their gender does not limit their interests - the same way parents of daughters want their girls to stay interested in science while twirling in a fancy dress”.

Dr Christia Brown, a professor of child psychology and the author of Parenting Beyond Pink and Blue, said: “The ripple effects of this can be profound: a boy who is affirmed and allowed to be his authentic, unique self grows up to be a man who is comfortable expressing himself, who can embrace those interests and traits that make him unique. Allowing young boys to embrace a variety of interests helps them grow up to be happier, healthier adults.”

This style of parenting is a strong counter to the cultural pressure of toxic masculinity – suppressing emotion and eschewing anything considered feminine – and therefore weak and inferior, said Melsky.

“Rather than pushing them away from what has been viewed as traditionally feminine, these parents are encouraging their sons to take a view that those things are compatible with – indeed, a desirable part of – having a male identity,” she added.