Trouble With Data Length in geom_alluvial

[cmenick]

I am attempting to use a column of color codes to manually fill the flows while using geom_alluvial. When I use this however, I get the error that "! Aesthetics must be either length 1 or the same as the data (13800) Fix the following mappings: fill". However, in this case, 13800 does not match the length of my data (52986). I see the same pattern with other datasets, where the length of the data within geom_alluvial is different than the actual, and is always a number rounded to the nearest 100. The chart appears as it should otherwise.

What determines the length of the data in geom_alluvial, and why is it different than the length of the data?