Tracee Ellis Ross on Why 'Mixed-ish' Is The Perfect Addition to the 'ish' Universe

The spin-off series follows Tracee Ellis Ross' 'Black-ish' character, Rainbow, as she grows up in a mixed-race family in the '80s.  'Mixed-ish' premieres Tuesday, Sept. 24, at 9 p.m. ET on ABC, joining the 'ish' Universe alongside 'Black-ish' and 'Grown-ish.'