I did a slapdash, very non-scientific test of one of the orange papers this evening.
I have no idea if this happens when one is laying down too much sensitizer, but the middle of the sensitizer blob stayed a blob, while the outer edges which I had coated more thinly, showed up as blue when exposed to my UV lamp. I am not sure either if the cyanotype solution itself is acting up, since it is out of date.
I am going to do another test, and get the sensitizer on a bit thinner. Perhaps it is a matter of getting less on there, and keep off flooding it, since the solution just bled through to the back of the paper. Anyways, I enjoy the surface, and I'll keep at it for a bit to see if I can get it to work. If it doesn't work, I'll draw funny birds on it instead.