Anne, it seems to me that you are down the wrong path with your 5BG trials.  From the pure dyes spread sheet you have the Turq at DOS 1% at 2.5B 7/8 and 92% Turq,  8% yellow at 2.5B 7/8 which is the same as the pure turq.  I don't think that the yellow is doing anything.  The yellow is so weak tinorially that it is lost in all that turq., try gold it is stronger and more likely to change the hue of turq at low levels.