The basic uniform of Spanish colonial troops was made from a fabric known as Rayadillo; this was white with fine blue stripes, roughly ten stripes per inch and therefore challenging to paint! I have seen figures painted in pale blues to represent the fabric but I opted to paint a base coat of white and covered it with a very pale blue wash. I was reasonably happy with the results and went on to complete the rest of the uniform. Collars and cuffs were green for infantry and red for all other units. Belts, boots, packs and so on were black or brown. Hats were mainly straw and were painted as such with the Spanish roundel (red, yellow, red) on the right hand side.
American Civil War cavalry were used to produce lancers; apart from the paint work they just needed pennants adding: