code: def set_theme(theme=None, for_code=None):
      
      try:
          if theme == 'default':
              return
          theme = theme or os.environ.get('AXC_THEME', 'random')
          # all the themes from here:
          themes = read_themes()
          if theme == 'random':
              rand = randint(0, len(themes)-1)
              theme = themes.keys()[rand]
          t = themes.get(theme)
          if not t or len(t.get('ct')) != 5:
              # leave defaults:
              return
          _for = ''
          if for_code:
              _for = ' (code)'
          if is_app:
              print >> sys.stderr, low('theme%s: %s (%s)' % (_for, theme,
                                                         t.get('name')))
          t = t['ct']
          cols = (t[0], t[1], t[2], t[3], t[4])
          if for_code:
              global CH1, CH2, CH3, CH4, CH5
              CH1, CH2, CH3, CH4, CH5 = cols
          else:
              global H1, H2, H3, H4, H5
              # set the colors now from the ansi codes in the theme:
              H1, H2, H3, H4, H5 = cols
      finally:
          if for_code:
              build_hl_by_token()
docs: set md and code theme