The present investigation aimed to determine the optimal parameters for wire-cut electrical discharge machining (WEDM) for stir cast aluminum alloy AA6063 at 850°C reinforced with 10 wt.% green SiC (SiCg) and black SiC (SiCb) particles. The WEDM machining parameters, such as pulse on time (TON), wire feed (WF) rate, and flushing pressure (FP) of the resultant stir cast AA6063/SiCb and AA6063/SiCg composites, were optimized using the Taguchi method with L9 orthogonal array to estimate the responses, such as surface roughness and metal removal rate. Further, through grey relational analysis, the finest parameters for WEDM of AA6063/SiCb and AA6063/SiCg composites were evaluated as TON = 50 μs, WF rate = 18 m/min, and FP = 3 MPa. With the optimum parameters obtained, conformational experiments were conducted, and the scanning electron microscopic images were recorded, along with the energy-dispersive X-ray (EDX) spectroscopic data of the worn surfaces and debris. From the EDX mapping images of the machined surface, it was evident that AA6063/SiCb displays a more polished surface than AA6063/SiCg. However, for applications requiring a high metal removal rate, AA6063/SiCg displays better results than AA6063/SiCb.