多颜色识别时，有黄色和蓝色时，print(blob.code())输出不应该是6嘛？但输出是2 4，请问这是为什么？

[wnhp]

import sensor, image, time, math

thresholds = [(70, 30, 25, 61, 32, -22), # generic_red_thresholds -> index is 0 so code == (1 << 0)
              (31, 95, -1, 53, 71, 17), # generic_YELLOW_thresholds -> index is 1 so code == (1 << 1)
              (75, 25, -18, 22, -21, -63)]# generic_blue_thresholds
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False) # must be turned off for color tracking
sensor.set_auto_whitebal(False) # must be turned off for color tracking
clock = time.clock()

while(True):
    clock.tick()
    img = sensor.snapshot()
    for blob in img.find_blobs(thresholds,merge=True, pixels_threshold=200, area_threshold=200): 
        img.draw_rectangle(blob.rect())
        img.draw_cross(blob.cx(), blob.cy())
        print(blob.code())

[kidswong999]

黄色的二进制是010，所以是2
蓝色的二进制是100，所以是4