I don't think there is an actual yellow in this marble, it looks to me like its a deep orange or red, but thin over the opaque white, which is making it appear yellow if that makes sense.
I looked and looked at several different ketchup and mustards, and as much as I want it to be one, I don't think it is. I'm having a hard time distinguishing ribbons, but only because I'm not too familiar with Pelt construction.
A bloodie? I'll start looking those up
And do you have a name for it MC Marbles?