color3f color spaces

[dgovil]

I just wanted to discuss some color management details before I start writing up code for a PR.

Currently mayaUsd only writes out color space attributes for exported textures. This is really nice for tooling that can't guarantee being run in an environment with a studio or show color management setup.

However all color3f attributes don't write their color space metadata out. It looks like they actually write out the colors in a raw color space or whatever the Rendering space is set to.

Since it's ambiguous what color space the color3f attributes are written to, I'd like to add metadata that's similar to the one that is written on textures. However I want to confirm what color space these values are written in?

Would you be able to provide pointers on the color space used for the written values? Is it safe to assume these are in the rendering color space?