Need to configure palettes manually, since we are checking stderr.

def _find_palettes(stream):
    ''' Need to configure palettes manually, since we are checking stderr. '''
    chosen = choose_palette(stream=stream)
    palettes = get_available_palettes(chosen)
    fg = ForegroundPalette(palettes=palettes)
    fx = EffectsPalette(palettes=palettes)
    return fg, fx, chosen