So having perused through the Army lists/Childs "The Army of Charles II" and Charles Dalton's "The Scots Army 1661-81" I've found no information regarding the blue uniforms reference. Haven't been able to get hold of Stuart Reid's Partizan Press book in any Scots libraries, so not sure whether that has any further information in or not. However talking to Stephen Ede-Borrett, who is very well versed regarding the period, he feels a standardisation of bonnets would not be widespread, even in the Civil War. As for the coats, the price of blue cloth, compared to red or undyed grey cloth, supports the latters predominance among Scots Militia during the Covenanting period. Any further insight from anyone with further research/the Reid book would be much appreciated.