[jimm]

The "red text" suggestion won't work for some color-blind people. There's got to be some non-color visual representation of the state.

[jacobolus]

Even monochromats can differentiate red from black, because the black is substantially darker. (Which isn't necessarily to say that adding other cues isn't also a good idea.)

[mikeryan]

True but its consistent with the current UX which indicates missed calls in red (if you're looking at All recent calls)