Virgin vinyl is clear. Colored vinyl only adds some dye. In the 50's thru the 70's unsold records were often ground up and added to the virgin black vinyl, results were bits of paper in the vinyl. This would cause tics and pops. in 1968, I purchased some very cheap records in Kaoshung, Taiwan. The Taiwanese recordings were all bootlegs. Due to their composition, they were good for 3 maybe 4 plays, the records did not contain any hardening agents and were very soft in the grooves. In the 70's Euro imported records were the best, especially sound quality. Imho virgin vinyl is generally the best recording.