Hers a great site to give you some ideas for the colours of your horses.
http://sweetheartsofthewest.blogspot.com/2015/04/a-horse-is-horse-breeds-common-in-old.html
Great western film on TV today 'The War Wagon'. Great game scenario.
That's a great find, Les - first one of it's kind I've certainly come across.
From a more general horse colours and markings perspective, I find Henry Hyde's guide very useful:
(https://pbs.twimg.com/media/CUsgztIWoAAqWl_.jpg)
Henry's guide is great Simon.
That is all very illuminating. Thank you.