There is definitely a bias in towards assuming whiteness in online trans spaces. I'm not black, but I'm undeniably not white, and I do often notice white European beauty standards being a pervasive assumption for transfems. It doesn't feel entirely exclusionary because there's still so much common ground, but there are small moments like where it's noticeable.

Things like the types of makeup people recommend don't apply to all skin tones. Laser hair removal or IPL can't work unless you have fairer skin and darker hair. Most importantly, the experience of having to deal with racism AND transphobia just isn't talked about. White people tend to view black people as aesthetically more masculine and Asian people as more feminine, which can factor into how you pass to white people differently to people who look like you. Things become even more complicated and difficult to parse if you're more mixed or ambiguous, as some norms apply and some don't.

This isn't to say that white trans people are doing anything wrong. In many ways it's a natural consequence of what the most numerous group happens to be in the space. What is important to remember is that your community is not a monolith, so be accepting of differences and avoid generalizations.