Just ran into an issue with a shapemap where I added my location and my field for color saturation, and while there were hundreds of records difference in one map area to another, there was no discernable difference in color. In this example, I'm mapping the number of students in each state house district in Tennessee:
What I realized is that I had a lot of records that weren't relevant to the map - tons of records from outside Tennessee, in this case. It turns out the color saturation is taking into account the tens of thousands of records thta have a blank value for the map key.
If I add a visual filter to filter out those students, my saturation turns normal.
As soon as I filtered out the records that didn't apply to the map, my saturation was reasonable again:
