Is white mold worse than black mold?

No. Color is a terrible ranking system. White, green, or black growth on wet building materials all mean the same practical thing: remove the colonized porous material, clean what is sound, and dry the area. Some white growth is even mineral salts or paint residue, which is why we meter instead of guessing from a photo.

The dangerous version of this question is the one that delays cleanup because the patch is 'only' white, or causes a panic because it is black. Look at the moisture.