"White" implies a specific equal energy per unit frequency
frequency profile of the noise.
"Pink" is equal energy per octave (or decade), logarithmic.
You can see sub-Hz activity in RTN (random telegraph noise)
and many semiconductor devices will produce white noise
(in current mode) which is transformed to pink with any
significant shunt C (corner frequency depends on the
source element Rout and Cshunt).
Now how a noise source enables a voltage measurement,
I couldn't say. Nor whether you really want white, pink
or plaid. Are you tasked with measuring the AC voltage
in a band surrounding 1Hz (+/- ?) To measure the voltage
at 1 second intervals?