It's not colorism for a white person- as the author of this piece- to write critically of what other white people in an organization the author resigned from in disgust and despair did.
This is not an issue that can be addressed at all by just reducing it to what some "bad individuals" did- and the only reason any of the people the author referenced in this piece did what they did and said what they said was that they identified as white.
The sort of white people who can't handle whiteness and white supremacism being referenced in a discussion like this are the sort of white people- and as a white person myself, it is both legitimate and an obligation for me to say this- who are incapable of being part of any sort of movement for justice.
It's better to focus on those who CAN be part of the solution than to try and appease those who can't.