Specifies which hyperplane arrangement to consider. By default (or by
explicitly entering "mct") it supplies the standard "Modal Color Theory" arrangements
of getineqmat(), but can be set to strings "white," "black", "gray", "roth", "infrared",
"pastel", "rosy", "infrared", or "anaglyph", giving the ineqmats of make_white_ineqmat(),
make_black_ineqmat(), make_gray_ineqmat(), make_roth_ineqmat(),
make_infrared_ineqmat(), make_pastel_ineqmat(), make_rosy_ineqmat(),
make_infrared_ineqmat(), or make_anaglyph_ineqmat(). For other
arrangements, this parameter accepts explicit matrices.