In the image above, the coating of these parts ranges from .0003″ on the left to greater than .002″ on the right. All are undyed.
“Clear” anodizing is really a misnomer, as undyed anodizing is not really clear.
“Clear” anodizing varies from a very light gray for very thin coatings (.0001-.0003″) to a dark olive color for thick Type III coatings (.002 or greater). Very thin clear anodizing (sometimes called “cosmetic” clear) coatings mimic the look of bare aluminum (though the coating is actually slightly gray), hence the term “clear” anodizing. But on thick hardcoated parts, the coloring is anything but clear.