How to change ion-radio icon and background, font color?

I have been developing a Ionic app.
I am gonna ion-radio in my app.
I worked with ionic demo source, but ion-radio icon is not same to demo.

My App
Screenshot at Aug 16 10-12-20

And my design

I am a begginer, so I don’t know how to change it.
I want you to help me kindly.