Typically described as bronze but varies, sometimes slate gray.
"Colour matching of hard anodised parts is near impossible, with too many variables on the parts, their method of manufacture, their heat-treatment, as well as in the details of the process, all conspiring to produce unpredictable changes in hue and shade."
The shock absorber tubes (inside the coils) in the photo below are fairly typical color for about 0.0015-0.002" (40-50 [μ]m) thick hard anodize on 7075-T6:
Dichromate sealing will add a yellowish tinge, making an olive color.
Hard anodize can also be dyed black or (less successfully) other colors.