Photography: When Canon 6D shot the evening scene with M file, the photo was blue and the color was particularly cold. I want to know what the problem is. Manual mode of 6d night shooting

If automatic white balance is used first, an inappropriate white balance may be set.

If the night scene is rigorous, you need to use an exposure instrument to get the exposure time. If it is within 30 seconds, hand it over to the camera for metering. Of course, if there is no exposure meter, you can estimate a time and directly use it as the exposure time.