A STARZ Original Series From Executive Producer Ronald D. Moore: Outlander

[Carlo]

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Therefore I believe that it would have been very historically inaccurate, to have the cast wearing Victorian invented "clan tartans", esp. the predominantly red "dress tartans", as I believe we have been told that only the rich could have afforded such colours, in their clothing. I also seem to recall reading that wearing a mix of different tartan patterns was not an uncommon practice, before the banning of tartans.
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I have read on different occassions, that the English army used red coates because the red dye was cheap.