Canon EOS 250D Advanced User's Manual page 214

Peaking display is not shown during magnified display.
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MF peaking may be hard to discern at high ISO speeds, especially when ISO
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expansion is set. If necessary, lower the ISO speed or set [Peaking] to [Off].
Peaking display shown on the LCD monitor is not recorded in images.
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3
Set the level and color.
Set it as necessary.
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214