[Poalim]

Grado SR60i and Colorfly C3 is good combination?

For pop, rock music

 

[tattoou2]

Yes and no.  I had a Colorfly C3 for a short while and then upgraded, but the C3 and the SR60i have fairly decent synergy together, but you may find the C3 struggling at times to provide enough power.  The rather thick cable of the SR60i limits it.  My PX200 and Fidelio L1 were really a much better match.
 
I received an AK100 over Christmas and didn't encounter any of the C3's limitations using my Grados.