I am leaning towards a fungal infection, primarily powdery mildew. Powdery mildew looks different on succulents, and doesn't present itself as a dusty white coating like you see on ornamental plants. Powdery mildew is usually a problem when humidity is high, and worse with a lack of good air flow. Anthracnose is another fungal infection that can affect jades, causing leaf spots like that, but the "starting out white" part says powdery mildew. Either way, fungal treatment may help, but those leaves are scarred permanently. Also, I'd isolate the infected plants from everything else, and treat everything regardless.

P.S. Pay attention to label directions for any treatment you use, if you go that route.

Joe

Myjade plant has black spotd on some leaves, its on a Sun porch with open windows so i dunno what i could be other then water sitting on the leaves causing mold?
Hope your plants make it thru this, good luck