The Volume Sample RGB shader will sample a volume channel of the new volume API. It should be plugged into one of the components of the 'volume_collector' shader (in Source==Parameter mode) if you need to further edit the result of the reading of a channel, for instance to color correct it, etc.
Both the 'Volume Sample Float' and 'Volume Sample RGB' shaders share the same Sampling controls, the only difference being the type of the output, RGB or float.
These parameters are not texturable due to performance reasons.
An object space offset to apply to the volume sampling position when using named channels to fetch the volume data. This is useful to displace the volume data.
You will need to connect a noise texture to the position offset to see any result.
The voxel interpolation to use when sampling the volume data using named channels.
Apply a gamma correction to the color.
Scale values around the Contrast Pivot.
The origin of the contrast scaling. The default is 0.18, the average perceptual mid-gray.
Multiply the color using a photo f-stop scale, where an increment of 1 doubles the luminosity.
Multiply the color by this factor.
Add this value to the color.