We present an improved comparison of the strong coupling of the gluon to light (ql=u+d+s), c, and b quarks, determined from multijet rates in flavor-tagged samples of hadronic Z0 decays recorded with the SLC Large Detector at the SLAC Linear Collider between 1993 and 1995. Flavor separation among primary qlql, cc̅, and bb̅ final states was made on the basis of the reconstructed mass of long-lived heavy-hadron decay vertices, yielding tags with high purity and low bias against ⩾ 3-jet final states. We find: αsc/αsuds=1.036±0.043(stat)-0.045+0.041(syst)-0.018+0.020(theory) and αsb/αsuds=1.004±0.018(stat)-0.031+0.026(syst)-0.029+0.018(theory).