What does the option do "cls"?

I’m trying to understand what the “cls” option does: “”.

but it gives me no information.

I think I understand that a css class applies to the field, is it correct?

I’m trying to apply the class “cls” to the field: “uk-width-medium-1-6” but this is not applied.

Color field:

  "cls": "uk-width-medium-1-6",
  "spectrum": {
    "preferredFormat": "hex"

Use of the Master branch cockpit


The class should be applied to the field, but it looks like if it is missing in the color field. I never really used that feature because of its behaviour. Normally I don’t need a class for the input, but for the outer container of a field.

It should be fixed with adding

if (opts.cls) {