My phone is a Samsung Galaxy Y phone. I do not want my Gmail contacts in the phone contacts. I have disabled automatic sync. There seems to be no direct way to delete them
To completely remove them from device, go into:
Settings -> Accounts and sync -> (select your account) -> Turn "Sync Contacts" off
Now delete Gmail contacts from your phone:
- Use the method @Ames suggested to filter out Gmail contacts only
- Delete all contacts (only Gmail ones will get deleted)
- Revert to displaying other contacts.
Since Contacts will not be synced, this will neither delete your contacts from web version of Gmail nor bring them back to your device. Just be careful not to turn this setting back on.