See
ASTM B580 – Standard Specification for Anodic Oxide Coatings on Aluminum
ASTM B136 – Standard Method for Measurement of Stain Resistance of Anodic Coatings on Aluminum
Cleaning, Desmut,
Sulfuric acid, 15% 12 a/sf at 18-24 v. 70F for 10-60 minutes
Dye
Boiling water to seal
or http://www.google.com/patents/US3071494
