For the record; MIL-A-8625F does not list a "Type III Class 2" (dyed hardcoat) at least not in revision F which is the current one. Milspecs read like they were written by a "Philadelphia lawyer", so they're very easy to misunderstand. The same spec specifically does not recommend dyeing or sealing Type III layers, as this reduces it's mechanical abrasion resistance. In practice: because in Type III layers the anodize is dark yellow to bronze colored, very dark dyes, like black or dark green can only be used. The dyeing process is quite difficult.
The standard recipe for Type III (hardcoat) is 24 A/sq.ft. current density, at 32 deg. F, for an extended anodization time. I don't know what PAR would be for hardcoat yet, certainly higher than 2.5 Ohms per sq.ft.. The acid/water mix is the same for Type III and Type II. Reducing the acid concentration for Type III would serve to make the pores, already small from the high current density even smaller. Dyeing would become nearly impossible. Without this level of cooling (32 degrees), the dissolution will overpower the anodization and you will fail miserably. This requires very powerful agitation and a refrigeration type chiller. You would have little chance using ice.
Edited to correct 3 typos.
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