Why the same scene can look yellow, blue, or just right
Every light source has its own color temperature, measured in Kelvin, and a camera sensor has no built-in way of knowing which one it's looking at. Auto white balance makes its best guess based on the scene, but it can be fooled by mixed lighting, such as a room lit by both a window and a lamp, or by scenes dominated by one strong color.
When to trust Auto and when to go custom
Auto white balance is usually fine for casual daylight shooting outdoors. For events with mixed lighting, like a venue combining fluorescent ceiling lights, window light, and string lights, results can shift unpredictably from shot to shot, so it's worth setting an explicit preset, dialing in a custom white balance, or simply correcting everything uniformly afterward from RAW files.
Frequently Asked Questions
Why do all my indoor photos look orange without a flash?
Indoor incandescent or warm LED bulbs have a low color temperature, so without correction the camera renders that light source's natural orange cast onto everything. Switching to a Tungsten or Incandescent white balance preset, or fixing it afterward if you shoot RAW, removes most of that tint.
Does white balance matter if I only shoot JPEG?
It matters more with JPEG, since the camera bakes the white balance decision permanently into the file with limited room to fix it later. If you shoot JPEG regularly in tricky lighting, it's worth setting the white balance preset manually rather than relying on Auto.