Not every unit type would have the same secondary or even primary colors. As for the campaign map faction colors, this is slightely easier.

Great Britain: bright red
France: white
Spain: yellow
Russia: dark green
Prussia: grey or black
Austria: gold and black
Sweden: bright blue
Netherlands: orange
Portugal:light green
Bavaria: light blue
Ottomans:
Poland-Lithuania: dark red
Denmark:

Uniform colors:

Great Britain: primary red for all; secondary blue for royal regiments; yellow, green, black etc for other troops; primary blue with secondary red for artillery and some royal cavalry

France: primary white for all non-royal; primary blue for royal; secondary red for royal, non-royal secondary > most other colors

Spain:


Prussia: primary dark blue for all; secondary red and yellow for most units;

Russia: primary dark green and secondary red for all intantry; primary white for most cavalry

Austria: primary white for most units; secondary red for cavalry and some infantry, other secondarys for other units

Sweden: primary medium blue for all units, secondary yellow for almost all units

Netherlands: primary dark blue for all units; secondary orange > red for royal units; secondary other for other units

Portugal:

Bavaria: primary light blue for all infantry; primary white for cavalry (not sure); secondary white (or white & black) for royal units; other secondarys for other units predominating to red

Ottomans:

Poland-Lithuania:

Denmark: primary red for all units; secondary other colors


I don't have all of this finished, but this is the general idea. Many factions varied widely in uniformity of colors both over time and by regiment. Others, I don't have reliable sources for yet.

Chairman