That's the weathering tech I use.
But to dull paint like I stated, still looking for the pics.....
Before painting the figure....
Decide on the paint you want to use.
Look in your pastel chalks( get the largest size available, It will give you the most yield of colors to match your paints.) and choose the color that best matches your paint.
method 1:Take an x-acto knife and run it across the pastel chalk to make a fine powder.(the method I use)
method 2: use sand paper as seen in these pictures and make a fine dust with the sandpaper applied to the chalk.
These pics still aren't the ones I've been looking for....
But any way:
Once you have a nice amount of powder ready to go.
Get two brushes, one too paint and one too dust. (I always keep my dusting and paint brushes separate.)
Start painting the figure, vehicle etc....
Once paint is applied(water based only)
Take your dusty brush and dab into the powder(this is a feel or eye method to get the right amount)
As if your were putting on make up, dab the powder on the paint and start to drag the powder over the paint in a brushing method.
Let dry and repeat if you feel the need.
This will dull down the color, as well as add depth too it and possibly change the color for better.
Like in these customs I did:
The Cad Bane coat was originally a burnt umber(dark brown)
I add earth red to it with pastel chalks to give it that worn leather effect.
For Ulic, the blue was actually a normal dark blue, and the legs were british crimson.
I added light blue to the blue on Ulic's shirt to give it that bright blue look from the comics, and a dark blood red to the pants to give it that worn red look.
I hope this helps, again Im sorry I haven't found the pics yet.
Sorry I wasn't able to find the pics.....