Interface when there is an incoming call

[ahadinhhai (Ha Dinh Hai)]

Please help me set up interface theme change when receiving incoming calls.

[Adriraj_Saha]

What do you want to do…pls tell in brief

[ahadinhhai (Ha Dinh Hai)]

I want to change the incoming call interface
as this app: https://play.google.com/store/apps/details?id=com.colorcaller.colorphone

[deanart2012 (Dean Artis)]

What have you tried so far?

[ahadinhhai (Ha Dinh Hai)]

I don’t know which tool to use?