The change to using setters left a quirk from the previous un-mutable
design where you couldn't set values on an invalid color space and
create a valid one.
This changes that so it works as expected for an imperative API, but
is also needed for the declarative QML bindings.
Change-Id: I246cfc38b364b156238151c42c1df82a3f1cc9d3
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>