Hi Mike.
We have only natural color at this moment. It is a bit yellowish and slightly transparent white. So far, professional people, mostly industrial related, did test it and they said they do not need colored one. Even figure maker who makes human size anime character said they do not need colored filament because they give nice coloring on the surface. However, we haven't decide the timing but plan to make colored filament near future, maybe end of this year. We have selected dyestuff already. I suppose if red dye is added, the filament become matt pastel pink because glass wool won't be dyed.