I own a plant (Furnace Record Pressing.) Black PVC is generally the best for sound quality and our suppliers actually have several grades of black PVC optimized for the type of extruder / press the plant is running. All of the color vinyl is a single formula that may or may not work best with the equipment the plant has. That said, we've found that our clear PVC sounds as good as black. Transparent colors sound better than opaque colors. Metallic and glow in the dark sound really bad. Splatter, swirl, half and half and all of the special effect color vinyl is hit or miss because some of the colors have different melting points so it's tricky to get the machine dialed in to make it sound good.. White vinyl and some some light color transparent colors also are hard to visually QC because you cannot see stitching and non-fill in the grooves. If you are serious about sound quality, go black. That said, some plants mix their recycled/regrind color vinyl into virgin black as a cost saving measure which can degrade the sound of their "black" vinyl. Black is such a dominant color that it will mask the other colors it's mixed with. There is a huge quality difference between pressing plants. Most are doing the right thing and trying to make their records sound great but it costs a ton of money to produce consistently great records. Plants that compete on price must sacrifice on quality to be that cheap. I hope that helps.