Get value from input with class name in Figma

Question

I would like to get value from Figma Background Input.

var id = document.getElementsByClassName("raw_components--textInput--23_ta raw_components--base--3TpZG raw_components--input--13lRh raw_components--singleRowHeight--3PF2a background_panel--color--2TxAv paint_panels--colorInput--10RG5");

    console.log(id[0].value);

But I received nothing. I would like to replace automatically this value to other colour as Tampermonkey Script.