Field Cache density field colours mode unsupported

What is the technical reason that the density field mode Colours isn’t supported in the Field Cache node, as is stated in the manual?

We would like to render a scene starting from 30 seconds instead of 0 seconds, and are unable to do so as we cannot create a cache in Colours mode.

The Field Cache uses a high-compression codec which so far has only been designed to support densities/densities and temperatures modes. We may add colour support in future.

For now, you’ll have to adapt the current system to use of those, or
render the scene with a 30 second preroll, and edit it out after the fact.

Interesting. Yes, we’re doing the pre-roll solution for now. Thanks @ryan.notch.