I'm not sure if they've changed the material across the whole range or just on some flavours/markets. Certainly they used to be more opaque than the last few I've seen.

The simple basis is to use the normal tone scale 0-255. This relates to 8 stops in intensity.
0/2/4/8/16/32/64/128/256. You can see this on the Levels slider in PS and other software.
The best way to set white balance is auto and use RAW.