I have decided to give a short detail of how I quickly paint a unit of white summer uniform Mexicans. The method could easily be elaborated to other white uniforms (Austrian of 1809 for instance). To most people there probably wont even be anything new in any of this, but I post it in the interest of sharing knowledge. (And being thoroughly damaged by my scientific OCD of documenting). I value look over total historical accuracy also, so I beg your pardon if there's something that hurts your eyes.
But in order not to bore you I have recruited Gonzales Pablo el Culo, Mexican army recruiter.
Hola Señor!
So you would like to make a nice army for the ranks of the mighty presidente Santa Anna, eh?
Oh, but you are worried about how to get that nice shiny uniform for sooo many men, eh?
No worries señor! I show you!
First you find some gringos to use for the army! Then you get started! Santa Anna no like to wait!
White uniform will have white undercoat! Si!Start with the weak covering colours.
Stage 1: Red details (here Khardor base red P3)
Don't mind if you make a mistake! Be quick instead - we have a war to fight! Details can be corrected later. This is no siesta so get on with it!
Stage 2: Flesh (here Khardic flesh P3). Apply like a 'thick wash' - meaning thin it a bit.
Stage 3: Paint the rifle in brown (here Bloodtracker Brown P3)
Look, eh?! Is going fast already! Santa Anna will be pleased!
Stage 4: Skin gets a darker wash of flesh (Here Idrian Flesh P3). Boots get various colours. Shoes was a real problem, so a bit of variation shows this.
Si, the shoes! No es bueno... 
Stage 5: Paint the metal. (Here Shining Gold GW/Coat D'Arms and Boltgun Metal GW is used)
¡Dios mío! Careful with the gold señor! IS precious!
Stage 6: Hair and cap black! (Any black will do)
Stage 7: The pom pom is painted like a Mexican flag.
Viva!!!
Stage 8: The whole figure is washed with black wash (Here Armypainter waterbased black wash)
Puta!
Is all so dirty now! Santa Anna will not be pleased! Hurry señor and get these dirty gringos cleaned up!
But now first a siesta 
Thanks for looking. Part two will be around within the next couple of weeks.