How to replace input value using redux-form ? React

Question

I using redux-form to get value from input ->

          <Field
            id="primary-color"
            name="theme.primaryColor" <- How to get value
            component={ButtonColorPicker}
            label={intl.formatMessage(messages.primaryColor)}
          />

And this is work good but,

I want to replace this theme value sometimes.

I have dropdown when I want to change value ->

          <Field
            id="colorDropdown"
            name="colorDropdown"
            component={renderColorDropdown} 
            options={options}
            onChange={this.selectedColors}
          />

selectedColors is function

  selectedColors = (colors) => {
    let { theme, formValuesTheme } = this.props; 
    console.log("colors", colors); 
  };

I got good results but I want if not selected anythink i need to set:

          <Field
            id="primary-color"
            name="theme.primaryColor" <- How to get value
            component={ButtonColorPicker}
            label={intl.formatMessage(messages.primaryColor)}
          />

But if is changed dropdown to set selected ->

          <Field
            id="primary-color"
            name="NEW_SELECTED_VALUE" <- How to replace old value with new selected
            component={ButtonColorPicker}
            label={intl.formatMessage(messages.primaryColor)}
          />