Just make sure that desired base colors are more more saturated than the measured values.
Example: With an ISO of 100 R G B
Measured: 128 128 128
Desired 255 255 255
WB= 128 128 128 (Same as measured)
New ISO= 199.2188
Makes sense?
For all colors less saturated, the WB=measured Colors and leave the ISO alone; I think…, maybe not!