GPARTED on Raspberry Pi

I installed GPARTED on my Raspberry Pi without issue.  However I am having issues running it as it needs root access. I have crated my on root account and it isn't showing up in the identity drop down box.  Only two user accounts are listed - pi and root.  pi has been deleted and am not sure what the root is.  My question is why doesn't my personal account which has superuser permissions?

Thank you,
George