I suppose it depends on the bandpass of the filter. I have several older phones which can take (rear) images of IR leds - we used this as a sanity check at work several times. Images of normal things didn't look noticeably worse for having that sensitivity.

Many visible optical filters leak in the infrared, so perhaps a small amount gets through, but not enough to cause a noticeable colour cast in normal photography.

Vegetation in sunlight is a good test target, too. Leaves strongly reflect NIR.