questions about changing the color of whitewash...

I am almost done framing my shed which will have a cob infill in between the studs and I want to do a lime whitewash but I'd rather it not be blaring white. Can anyone offer any tips for darkening a whitewash? ...without compensating its effectiveness as an exterior finish? Id like to make it closer to the native on site clay we have, any tips regarding whitewash in general would be appreciated too, thank you!

I have no idea, but this is a really fascinating question! Here's a big BUMP!

You can add any alcaline resistant pigment to whitewash. As long as it makes up only a small fraction of the wash, it should not interfere with its properties. I just tried "Whitewash pigment" in google and got some interesting looking hits on the first page. I would probably try some finely ground charcoal, if i wanted to make my own pigment. Another way is to stain the finnished wall after whitewashing. This looks less homogenous, a bit more like watercolour, which can be really nice.

Iron oxide pigments will work. They are inexpensive, stable, non-toxic and available in all shades between black, orange-yellow and red. (Link for reference). I bought mine as "concrete color".

Any of the Mortar color pigments will work and if you want a pastel look you can even use tempra pigments (finger paints).