the areas subjected to laser pulses fig8 shows the same type of dyed anodized aluminum article with marks made with ir 1064 nm laser pulses note that the anodization is not bleached by the ir laser pulses and therefore does not reveal the aluminum color beneath beyond the translucency of the original oxide another aspect of this invention relates to laser marking anodized aluminum with colored anodization using picosecond lasers since anodization typically forms a porous surface dyes can be introduced which alter the appearance of the aluminum these dyes can either be opaque or translucent allowing varying amounts of incident light to reach the aluminum and be reflected back through the anodization fig7 shows an anodized aluminum article 80 with pink dye in the anodization and an array of marks 82 produced according to an aspect of the instant invention colors are created by bleaching the dye in the oxide layer as the aluminum underneath showed native silver color to a range of laser marked colors from shades of tan to gray and finally black these shades are created by varying the fluence of the laser pulses at the surface of the aluminum the four rows represent varying the pitch of the laser pulses from 10 to 50 microns and the columns represent varying the focal spot distance from the surface from 0 0 to 5 0 mm these laser parameters in all cases bleach the dye in the oxide overlaying the aluminum allowing the marks on the aluminum show through the laser marks optical density range from transparent to cie chromaticity less than l 40 a 5 b 10 laser parameters used to create these marks are given in table 3 bleaching of anodization dye is frequency dependent as shown.