the sims 4 dream home decorator has mario, luigi, wario, and surprisingly waluigi colored overalls as a swatch, and they even got the little details correct (luigi having darker blue than mario, wario having white buttons, and even waluigi being referenced at all)
While Mario references in other franchises are easy to come by, I feel like it's a struggle to name a franchise where that Mario reference is an integral part of the series. What do I mean by this? Take Kirby, for example: In that series starting from Super Star, Kirby wears a green pointed cap when he wields the Sword ability. It's very clearly a nod to The Legend of Zelda due to the reference to Link's signature cap (before Breath of the Wild upended the status quo). To this day, Kirby still wears this cap when he wields the Sword ability.
You know, speaking of The Legend of Zelda, I just thought of one: the character Talon (leftmost) is very clearly based on Mario, due to the portly figure, moustache, and the fact that he wears red and blue like Mario. His brother Ingo (rightmost) is clearly based on Luigi. I mean, his moustache is very reminiscent to Luigi's tidier and pointy one! Unlike many references, they are integral characters to the series and not some insignificant non-player characters. This is what I meant in the previous paragraph.