JSS - selector for all nested grand children elements

Question

First of all, I realize what a basic question this is, and for sure it has been asked before, I just can not find an answer to it.

Using JSS, I would like to have all the child elements, for example of <b>, and set a specific color to them. The <b> might be at any nesting level of root.

By trying the following, it selects only the immediate <b> childs of the root element:

const style = () => ({
    root: {
        "& b": {
            color: red;
        }
    }
})

So how can I select all children, regardless of nesting level?