Interpreting a bicolour sapphire takes a good understanding of light paths in the stone once cut, what you see on one axis is only part of the story, the next part is the cross table and how it absorbs/transmits light. To fully understand it is better to discuss the stone with the person who is going to cut it so you see how the cutter is interpreting the stone.
If blue on the C axis and yellow on the cross table, light traveling from blue through the yellow cross table is likely to come out green, so blue on the crown is not necessarily the best orientation whereas blue at the base of the pavilion will produce a totally different effect. Sapphire is also always cut between 7 & 15 degrees off axis, so that can change things again.
If you don't want to use a cutter on this forum, and there are some top notch cutters here, probably one of the best cutters for Sapphire would be John Broadfoot who is in Bundaberg. He is an acknowledged expert on Sapphire, extensively published and could probably be referred to a chief instructor for the AFG. He put together the recent AFG classes at the annual Casino event last month where I was studying gem repair and re-cutting.
If you want his contact details PM me.