Style.js

import color from 'color';
import { Platform } from 'react-native';

const platform = Platform.OS;
const header = {
  toolbarBtnColor: platform === 'ios' ? '#007aff' : '#fff',
  toolbarDefaultBg: platform === 'ios' ? '#F8F8F8' : '#3F51B5',
  toolbarHeight: platform === 'ios' ? 64 : 56,
  toolbarIconSize: platform === 'ios' ? 20 : 22,
  toolbarSearchIconSize: platform === 'ios' ? 20 : 23,
  toolbarInputColor: platform === 'ios' ? '#CECDD2' : '#fff',
  searchBarHeight: platform === 'ios' ? 30 : 40,
  toolbarInverseBg: '#222',
  toolbarTextColor: platform === 'ios' ? '#000' : '#fff',
  toolbarDefaultBorder: platform === 'ios' ? '#a7a6ab' : '#3F51B5',
  iosStatusbar: platform === 'ios' ? 'dark-content' : 'light-content',
  get statusBarColor() {
    return color(this.toolbarDefaultBg).darken(0.2);
  },
};
export default {
  Header: {
    headerTintColor: header.toolbarTextColor,
    headerStyle: {
      backgroundColor: header.toolbarDefaultBg,
      borderColor: header.toolbarDefaultBorder,
    },
  },
  statusBarColor: header.statusBarColor,
  iosStatusbar: header.iosStatusbar,
};