This is one place the ISOBMFF spec really screwed up, in my opinion. They should have included semantics for the colr box, i.e. which takes precedence. Intead

This is one place the ISOBMFF spec really screwed up, in my opinion. They should have included semantics for the colr box, i.e. which takes precedence. Intead we get: "Colour information may be supplied in one or more ColourInformationBoxes placed in a VisualSampleEntry. These should be placed in order in the sample entry starting with the most accurate (and potentially the most difficult to process), in progression to the least. These are advisory and concern rendering and colour conversion, and there is no normative behaviour associated with them; a reader may choose to use the most suitable."