In a large plastic container combine one part white chalk paint with 2 parts water. Add some brown craft paint to soften the white as desired.
Dip each pinecone into the water/paint solution.
Dry on paper towels slightly and repeat with a second or third coat of paint if desired.
Notes
You will need a plastic container large enough to dunk the largest pinecone that you are working with. If your pinecones are all small then you can use a smaller container.You can play around with the ratio of paint to water to create more opaque-looking pinecones.