How to edit texture pixel color

I cannot for the life of me figure out how to edit the color of pixels inside of a texture. I can access the data fine but every way I’ve tried to manipulate the actual color value results in the engine crashing. I feel like what I need is here: A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums but I have no idea how I would go about getting an array of color data into a void* to copy.