when the scale page button is pressed the 4 bottom rows represent the following:
row 5 - scale presets
row 6 - shared scales
row 7 - scale for CV A
row 8 - scale for CV B
let's forget about scale presets and shared scales for a second. each orca preset has 16 scales. no matter what you do CV A and CV B will always use one of these 16 scales. they're not empty by default - if i recall correctly they are prepopulated with the same notes as the scale presets. let's call them user scales.
the bottom 2 rows represent these 16 scales, there are 2 rows so that you can select different scales for CV A and B, but the same column in these 2 rows represents the same user scale. the one that is brighter is the currently selected scale (the one you touched last), and that's the scale that is open for editing when you go to the scale edit page.
now back to scale presets and shared scales, these are row 5 and 6 from the top respectively. whenever you press on one of these it will copy that scale into the currently selected user scale. these are not used by CV A and B at all (remember, it will always play from the 16 user scales), but selecting them simply copies them to whatever user scale is currently selected.
scale presets are just that, a quick way to set your current user scale to one of the presets (ionian, dorian etc). the shared scales are like scale presets that you can overwrite with your own scales (and since these are shared by all orca presets you can use them to copy scales between presets). you can't edit shared scales like you would with user scales. the only way to update a shared scale is by copying a user scale into it. if you don't need to copy scales between presets you don't need to use these shared scales at all.
hopefully this clarifies things a bit! good timing actually - i'm planning to do some work on orca soon, and among other things i'd like to redo the scale page. orca grew quite quickly and organically as evidenced by this thread, and as a result the UI is pretty confusing in places, the scale page being the worst offender - currently it carries too many functions with too many button combinations. i think it should be separated into 2 or 3 pages really, which hopefully should address some of the confusion. i'd love to hear ideas on how to improve this area, and any other improvements i should consider.