Sponge Tool for Saturation (Photoshop Elements)

How does the sponge tool work for saturation?

I was playing with the sponge tool (Photoshop Elements 2019) on two solid color patches, both with 50% saturation.

For Color 1 (RGB 42/80/65) the sponge tool did increase the saturation.

For Color 2 (RGB 255/192/129) the sponge tool had no effect. 

Also, trying the sponge tool on Color 2 while a different layer is set invisible sends the program into a long loop which eventually results in random black and white patches.