SpriteAtlas and proper use of Variant and animations

I'm struggling to wrap my head around what Variant/Master in the sprite atlas is actually for.
When i heard Atlas' were finally coming, I assumed this was for packing are remapping atlas at run time.
Overall this seems to be what it does... sorta... But variants. doesn't seem to to do much other than change scale and color mode...

I feel at this point i'm missing something. If I had 2 spriesheets one with a blue shirt a second with a red shirt, how do i would i 'swap' an atlas/sheet so that the animation looks at the right sprites?

could this be accomplished with 2 atlas masters and some kinda scripted sprite list?

The older methods were not very good and caused a massive fps loss.


Any pointers would be greatly appreciated.

BTW: the eclipse was awesome.