He (Tim Rudman) put some pix of example prints in the book (they're annoyingly good, too!) along with step-wedges and it is definitely a definite blue. The range available starts with a green-blue and ends up somewhere near a "Wedgewood" blue.
He does warn, however, that if you partially tone the print then it will need refixing or it will slowly print out over time.
If you need contact info for Speedibrews or the book ISBN then just say the word and I'll dig them out.
All the best
PS I've had a very thorough look through your website and I'm now officially a fan!
PPS If you strangle a smurf, what colour does he turn?