I signed up for Valhalla specifically to order from Saint_Symbiosis. I used to order on AlphaBay and never had any issues. Ordered 3.5g of coke from Symbiosis, received only 2g and on top of that the quality I received was subpar- there was string and some of the coke was yellow, though I tested it and it was positive for cocaine. He refused to offer any sort of customer service and told me my story was far fetched.
I know these sort of issues come with the territory of using the DNMs, but I still think it's helpful to share honest experiences with vendors so others are aware.
Some blow has a yellowish tint to it....I've seen straight off the boat yellow uncut blocks that was some of the best nose candy I've ever had. Friends of mine occasionally still ask if I'm ever going to run into my yellow friend again.
Yellow is not necessarily a bad thing.