Yes, you can set a custom White Balance. Take a look at the "White Balance parameter" section from the API Reference PDF:
White balance mode parameter
value explanation
"Auto WB" Auto WB
"Daylight" Daylight
"Shade" Shade
"Cloudy" Cloudy
"Incandescent" Incandescent
"Fluorescent: Warm White (-1)" Fluorescent: Warm White (-1)
"Fluorescent: Cool White (0)" Fluorescent: Cool White (0)
"Fluorescent: Day White (+1)" Fluorescent: Day White (+1)
"Fluorescent: Daylight (+2)" Fluorescent: Daylight (+2)
"Flash" Flash
"Color Temperature" Color Temperature
"Custom 1" Custom 1
"Custom 2" Custom 2
"Custom 3" Custom 3
White balance color temperature parameter
When a value of color temperature is -1, the parameter is invalid.
The below is a sample of color temperature range.
value explanation
[9900, 2500, 100]
[Maximum value, minimum value, step value]
In this case, it means that from 2500K to 9900K with 100K
increments in between.