Alain,
While doing this meditation, we suspend the breath for a very brief time before the entire inner colors are absorbed by the body. As for the outer colors, we are asked to imagine a pool of the outer colors flowing into the body. Are we not required to suspend the breath, as done for the inner colors? Do we simply visualize the outer colors flowing into the body and being absorbed?

Alternatively, if we allow the outer colors to fill up our lungs first, held in suspension, before being released into the body, just as done for the inner colors. This is just some loud thinking on my part.

I do wonder if I am being stupid in imagining it this way and will it be effective at all. Please clarify.

The process is exactly the same, as far as the breathing pattern goes, for the inner and outer colors.