Where is the blue default button?

Problem statement:
I used to like the blue default button a lot which is still available in Android Studio. 
Earlier I use to see the blue default button but after I updated or something the blue button vanished completely along with the other cool non-default button styles. 

Supporting information & attachments:
1. My Current IDE version: 
IntelliJ IDEA 2017.3.4 (Community Edition)
Build #IC-173.4548.28, built on January 30, 2018
JRE: 1.8.0_162-b12 x86
JVM: Java HotSpot(TM) Server VM by Oracle Corporation
Windows 7 6.1

2. Operating System: Microsoft Windows 7 Ultimate 32-bit (version 6.1, Build 7601: Service Pack 1)

3. Currently applied application theme: IntelliJ

4. Button styles I'm getting: 

(Note: Please ignore the visual styles and the font family and size of the dialog box as I've applied a different one for the OS other than the classical one, but I assure you that its not the reason of my problem. I've well verified this. So don't worry about that.)

5. Button styles I'm hoping to get:

(Source: (Google Images) Searched Internet for the same OS version.)

Request: 
1. Can anyone please let me know the fix, if possible?

Have a nice life ahead! :)