the black ones mark… even though it says non-marking on unicycle.com 
most ‘marks’ can easily be wiped off with a rag.
I bring one to our club meets, and it wipes off scuffs easily.
It’s the principle! Sure, you can rub the marks off, but it wasn’t supposed to mark! I hate things like that.
steve’s right! i spent 25 bucks on that!!! i hate those too!!! (its actually pretty hard to get the marks off!
the real reason i got a primo wall vs any other bmx tyre was because it comes in all those funky non-black colours.
I hope youg guys plan to write about the marks in the product review on Unicycle.com. Currently there are no revies for the Wall.
Daniel
I got mine in blue. Actually, on the Unicycle.com UK website it pretty much says the black tires are non-marking: http://www.unicycle.uk.com/shop/shopdisplayproduct.asp?catalogid=56
“…available in black and ALSO non-marking colors…”
I saw this and wrote to Unicycle.com here in the US and they said that any tire is going to mark, but the lighter it is the less it will mark.
Nikki
I meant to say marking, not non-marking.
Nikki
are the red/ blue marking? (megaspins…)
That’s the danger of saying “non-marking.” But it helps indoor riders if tires are divided among non-marking and “other,” as there is a difference.
As has been mentioned, any tire can make marks if you try hard enough. So can skin, non-marking shoes, and car paint. Non-marking tires generally have a softer rubber compound, making them less likely to make marks. Colored tires, in general, fall into the non-marking category. But with black, there’s a big range. Miyata black tires are hard to make marks with, but the average knobby tire, like a Gazzalodi, will do it much more easily.
In the gym where my club rides, the linoleum floor is especially sensitive to marks. One tool they have for cleaning up in there (90% of the marks are from other peoples’ shoes) is a tennis ball on the end of a stick. Slit an old tennis ball with an “x” pattern, and stick it on a broom handle or other thick dowell. Works for quite a while, and then gets replaced with a different ball. Much handier than crawling around on hands and knees!
Sorry about the confusion,
yes, too true. I thought that at unicon, after most of the freestyle stuff, I could see large white streaks on the floor. i’m not sure if it was the angle i was sitting at, but they looked quite apparent. Although they could have been from some converse shoes everyone was wearin (do they have a white sole??)
I thought that the softer compound tires would mark more than the harder compound tires. Because tires like the gazzoloddi are soft compound, and it marks quite a bit, and because of it’s soft compound, wears faster. So i thought the freestyle tires were a harder compund, and that they had a longer wear life. But this is all just me thinking 
oh well, Good luck with all tires, marking or non!
-Ryan