Add the ability to choose the opacity of the color, also an option like `--print-alpha` to append the opacity to the stdout when you use `--print`. So, when you use `kcolorchooser --print --print-alpha` it will return a color like `#ffffffff`.
Hopefully, this will implement alpha option in every other KDE application. QColorDialog has it since ages. It is very annoying to open Inkscape every time just for this.