Detailing here for future reference.
In the official Cooler Master application, upon saving set mirage frequencies, a transfer is initiated with the following byte pattern:
51 71 00 00 01 00 ff 4a 02 RR RR RR 03 GG GG GG 04 BB BB BB
RR RR RR corresponds to the red frequency,
GG GG GG to green, and
BB BB BB to blue.
The formula used to convert the input frequency to the output bytes has been painfully reverse-engineered. The bytes can be directly converted to a floating-point number via the following formula:
(first + 1) * third.second, where
third is the integer part of the number and
second is the decimal part of the number in a hexadecimal . This corresponds to the expression
187498 / x, where
x equals the input frequency. This can be (and has been) verified by manual calculation and non-linear regressions.
The final equation for calculation is the following:
187498 / x = (first + 1) * third.second