TIDA-00161: Refresh rate of LED module

Tool/software:

Hi all,

I currently want to understand the test results of TIDA-00161. The visual refresh rate of 3.5kHz is clear so far (33 MHz / 32 / 257) with 1 us pause each results in approx. 3.5 kHz.
The refresh rate of 60 Hz with an SPI of 6 MHz is also clear so far.
What I don't understand is why the refresh rate is not reduced, as one complete cycle for the grayscale clock results in approx. 16 Hz (3.5 kHz / 256 cycles).
How does a refresh rate of 60 Hz come about, or how does a grayscale with 14 bit come about?

Can anyone help me here?

Many thanks!