Vinyl composition effect on noise floor


So here's a curious thing I noticed today. Red vinyl is noisier than black! Ok, that's not true exactly, but check this out. I have a record that's half red, half black. I noticed after cueing up the record but before the music started that there was a distinct increase in the level of background noise when the stylus traveled into and through the red half, then a decrease when it went back to the black.

So, what would cause this? Because it's the same record, everything about the two halves must be the same... same master, same stamper, same pressing equipment, same packaging, same cleaning before I played it, same stylus in the groove, etc. Everything, that is, except the composition of the vinyl itself. Now, I know full well that color has nothing to do with it; I've got several very quiet colored discs and several noisy black ones. But I hadn't considered before that the makeup of the raw vinyl itself could be this important to a quiet background. Makes me want to get more info from pressing plants about how they source their vinyl. Thoughts?

Here's a video of the record spinning so you can see for yourself. Please excuse the poor quality, and turn up your speakers. http://vimeo.com/24946684
scissorfighter
I own only one vintage red vinyl LP. Linda Ronstadt, Back in the USA (Asylum 1977?). The vendor "warned" me that red vinyl doesn't sound as good as black vinyl. But guess what?? I really don't care.

Linda was in her late 20s or early 30s when the LP was released. The picture inserts are various shots of Linda wearing shorty-short-shorts in roller skates. Linda Ronstadt was one major cutie-pie back in the day. My wife threatens to confiscate the album.

A side benefit of owning the album are the cuts. Linda Ronstadt can really belt out a song. I think she's one of the most versatile artists around. I believe she has done rock, pop, country, Latin and maybe even tried her hand at opera. It's a great LP, great pics of LR, well recorded and it's red.

BTW, did I mention there are some great pics of LR wearing shorty-short-short and roller skates?? I love this hobby!
I think maybe you guys are talking about two different things? Picture Discs, (like Linda and Boston and many others) were never really meant to be played. I have quite a few that even came with a sticker or a note that said "not to be played".

Colored Vinyl is usually a solid color, (or two) with no pictures. I have many of these also. I have almost always found that the colored vinyl sounds worse and has more surface noise than standard black vinyl. Don't know why, but they usually do. I thought it had to be the process or the dye used to make them.
Mofi, my LR record is real and can be played. It really doesn't sound all that bad. It's definitely not a picture album. BTW, the name of the album is Living in the USA, and as I found out after reading a Wikipedia write up on LR, the LP sold pretty well in its day.
In the black vinyl is more soot. This softens the vinyl and reduces noise in general. Promo-Copies for example have much more soot inside than normal pressings.
My guess is that the surface noise could be due to the level of impurities that were in the color concentrate that was added to the vinyl.