Tonysince Im not familiar with your method its kind of difficult to make suggestions but from looking at your results there are several thing that come to mind.
If you are using bone meal, which I think you said you were, it may still have some impurities in it, that could be whats causing some of those little spots within the blues.
Your crucible should be big enough to be able to hold a frame in it with enough charcoal surrounding the parts as to have it hit the water in a carbon envelopeif they get flashed on the way in youll get poor results.
Tap water works just fine, just make sure its cold. All aspects of the process are important but you should put special emphasis in controlling the quench.
Everyone does something different, what works for me might not necessarily work for you, so at the risk of being vague, you are getting good colours in some areas the thing to do is to understand why the colours are strong there.persevere and you will succeed!
CJ
