One of the things I really dig about Invader Zim is that Zim wears a pink dress, but literally nobody comments on it. It’s never joked about, and nobody makes fun of him for it. In other kids’ cartoons like Fairly Odd Parents, Timmy wears his signature pink hat and shirt, is made fun of frequently for it, and it’s later revealed that he wears pink because his parents were expecting a girl. For Zim though, his invader uniform is just…not a subject for discussion, even from the school bullies.
And even more generally, the way pink is used in IZ is different, especially when you consider the prevalence of the color among Irkens in general. Pink is not associated with softness/emotion as it is in Steven Universe, nor does it serve to contrast the violence of the Irken empire, like the way Professor Umbridge from Harry Potter is deliberately soft and pink to contrast her vile personality. In fact, there’s no femininity/softness/elegance associated with pink in IZ whatsoever. The Massive is magenta, the fleet is pink, their uniforms are pink, they fire pink lasers to eradicate all organic life on a planet. There’s no beauty in it despite the destruction; pink is fully incorporated into the violence. Pink is powerful.