Already answered you on the LAF forum, so my post here will be substantially the same : drummers in the Dutch army normally wore reversed colours in order to stand out among the rank and file, so your lad should be wearing a yellow coat faced white, with or without white lace in keeping with the button colour.
Below is a watecolour of a a musketeer from the Van Essen regiment circa 1691, courtesy of the Legermuseum in Delft and Motorway's blog :
And here's a drummer from regiment van Wijnbergen wearing a musician's uniform in reversed colours (Wijnbergen had grey coats faced red) :
Hats and breeches of various colours would seem appropriate to me for Dutch infantrymen, especially if you're depicting troops from the 1670's.
One morning I shot an elephant in my pajamas. How he got into my pajamas I'll never know.