Canon EOS REBEL T8i Advanced User's Manual page 291

[ ] Auto White Balance
With [ ], you can slightly increase the intensity of the image's warm color cast when
shooting a tungsten-light scene.
If you select [
1.
Select [
2.
Select [
3.
Select an option.
], you can reduce the intensity of the image's warm color cast.
: White balance].
].
With [ ] selected, press the < > button.
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