It could be pretty helpful to be able to put in an option for helper text, similar to what you have in other parts of the admin UI. For example, what you see when opening up the settings and hovering over the Dynamic Content checkbox.
I could imagine passing an additional option for something like this as helper (but a better name than that) and having the result be a little box with that text appears on hover. Would be very useful for end users. But also just reminders for ourselves for what we want there.
"color" : {
"label" : "Primary",
"type" : "color",
"helper" : "Select a primary color to use for this field"
}