_showColorPicker () {
    if (typeof this.editor.options.onColorPicker === 'function' && this.dom.color) {
      const node = this

      // force deleting current color picker (if any)
      node._deleteDomColor()
      node.updateDom()

      const colorAnchor = createAbsoluteAnchor(this.dom.color, this.editor.getPopupAnchor())

      this.editor.options.onColorPicker(colorAnchor, this.value, function onChange (value) {
        if (typeof value === 'string' && value !== node.value) {
          // force recreating the color block, to cleanup any attached color picker
          node._deleteDomColor()

          node.value = value
          node.updateDom()
          node._debouncedOnChangeValue()
        }
      })
    }
  }
Open a color picker to select a new color
@private