curses.use_default_colors()
for i in range(0, curses.COLORS):
    curses.init_pair(i + 1, i, -1)
try:
    for i in range(0, 255):
        stdscr.addstr(str(i), curses.color_pair(i))
except curses.ERR:
    pass
stdscr.getch()
curses.wrapper(main)
How to use terminal color palette with curses