Perfect rhymes:
* Connell
* Donnell
* Fontainebleau (French town name)
* Grenfell
Near rhymes:
* Carole
* Carroll
* Control
* Enroll
* Extol
* Payroll
* Role
Eye rhymes:
* Barrel
* Carol
* Coral
* Farrel
* Kernel
The best rhyme for "colonel" will depend on the context of your writing or speaking.