This is most likely not a focus or wavelength issue — the red channel is clipped (blown out). In that area, the image data is effectively maxed out in red, so the surface loses normal texture and tonal variation, which makes it look flat and unnatural.

It can also appear oddly sharp because the boundary where the red channel clips creates a hard edge, giving a false impression of better focus.

A possible reason is that the surface was painted with a very bright or fluorescent red paint, which can reflect or emit unusually strong red light and push the red channel into overexposure even when the rest of the scene looks fine.

To avoid this, watch the RGB/color histogram rather than only overall exposure, and reduce exposure if one channel is clipping. Shooting RAW helps, but once a channel is fully clipped, lost detail usually cannot be recovered.