palette_dict = {
    'rainbow_cycle'           : ('o',3,0  ,999), # perceptive rainbow
    'rainbow_cycle_rev'       : ('o',3,999,  0),
    'rainbow'                 : ('o',3,107,893),
    'rainbow_rev'             : ('o',3,893,107),
    'rainbow2'                : ('s',3,167, 833), # cartesian rainbow
    'rainbow2_rev'            : ('s',3,833,167),

    'gcbmry' : ('r',3,166,999),
    'yrmbcg' : ('r',3,999,166),

    'cbmr'   : ('r',3,166,833),
    'rmbc'   : ('r',3,833,166),

    'green_yellow_red'        : ('s',3,500,833),
    'red_yellow_green'        : ('s',3,833,500),

    'yellow_white_blue'       : ('w',3,  0, 83),
    'blue_white_yellow'       : ('w',3, 83,  0),

    'blue_white_red'          : ('w',3, 83,167),
    'red_white_blue'          : ('w',3,167, 83),

    'red_white_green'         : ('w',3,167,250),
    'green_white_red'         : ('w',3,250,167),

    'green_white_magenta'     : ('w',3,250,333),
    'magenta_white_green'     : ('w',3,333,250),

    'magenta_white_cyan'      : ('w',3,333,417),
    'cyan_white_magenta'      : ('w',3,417,333),

    'cyan_white_yellow'       : ('w',3,417,500),
    'yellow_cyan_white'       : ('w',3,500,417),

    'yellow_white_green'      : ('w',3,500,583),
    'green_white_yellow'      : ('w',3,583,500),

    'green_white_blue'        : ('w',3,583,667),
    'blue_white_green'        : ('w',3,667,583),

    'blue_white_magenta'      : ('w',3,667,750),
    'magenta_white_blue'      : ('w',3,750,667),

    'magenta_white_yellow'    : ('w',3,750,833),
    'yellow_white_magenta'    : ('w',3,833,750),

    'yellow_white_red'        : ('w',3,833,917),
    'red_white_yellow'        : ('w',3,817,833),

    'red_white_cyan'          : ('w',3,916,999),
    'cyan_white_red'          : ('w',3,999,916),

    'yellow_blue'       : ('c',3,  0, 83),
    'blue_yellow'       : ('c',3, 83,  0),

    'blue_red'          : ('c',3, 83,167),
    'red_blue'          : ('c',3,167, 83),

    'red_green'         : ('c',3,167,250),
    'green_red'         : ('c',3,250,167),

    'green_magenta'     : ('c',3,250,333),
    'magenta_green'     : ('c',3,333,250),

    'magenta_cyan'      : ('c',3,333,417),
    'cyan_magenta'      : ('c',3,417,333),

    'cyan_yellow'       : ('c',3,417,500),
    'yellow_cyan'       : ('c',3,500,417),

    'yellow_green'      : ('c',3,500,583),
    'green_yellow'      : ('c',3,583,500),

    'green_blue'        : ('c',3,583,667),
    'blue_green'        : ('c',3,667,583),

    'blue_magenta'      : ('c',3,667,750),
    'magenta_blue'      : ('c',3,750,667),

    'magenta_yellow'    : ('c',3,750,833),
    'yellow_magenta'    : ('c',3,833,750),

    'yellow_red'        : ('c',3,833,917),
    'red_yellow'        : ('c',3,817,833),

    'red_cyan'          : ('c',3,916,999),
    'cyan_red'          : ('c',3,999,916),
    }