How to change default colors of colorNumberPicker?

I made an extension for a RGB-Colorsensor. I want the user to chose which color to recognize and wanted to change the colors of the colorNumberPicker to match better. But I can´t find informations on how to do it. //% color.defl=0xD4A012 only changes the current color but nothing of the picker.
Can anyone help?

/% color="#D063CF"
namespace rgb {
//% block=“show color $color”
//% color.shadow=“colorNumberPicker”
export function showColor(color: number) {