Colorado maduro is the wrapper color between colorado (reddish-brown) and maduro (dark brown to nearly black). It is darker than a typical natural wrapper but has not been fermented into a full maduro.
Like the other color names, it describes how the finished leaf looks, not the seed, the country, or the strength of the cigar. Factories do not all draw the line between colorado maduro and maduro in the same place. See wrapper types and colors.