I use a lot of loose round needles for black and grey. Even more so I use a lot of tight rounds for detail shading. I do the same with color too, but I tend to work more in black ad grey. At some point there was a crossroads and everyone started saying that mags were the only way to do color and shading. But at one time everything was done with rounds. It is just what works best for you.

There is a forum member Otto that does killer color work all with rounds.