I've created this rough diagram showing shield colours and patterns of the Zulu regiments at Isandlwana. I have gathered these from the internet. These will provide me with a rough guide to the units and where they were on the field. This might be of use to someone collecting a Zulu army and wondering about shield colours and patterns.
Basically the young unmarried, fast regiments were on the horns with the darker shields. The veteran married units formed the chest and loins, they tended to have lighter shields with more white on them to show their status.