Comment from CarbonPixel:

Currently there’s a bug where if you switch to third person view while your character is standing in active rain, you can see a few seconds of the Blood, Sweat, and Tears VFX overlay feature that isn’t officially released yet. The effect only lasts a few seconds once you switch and turns off consistently but it resets when you switch camera modes from first to third person again. You can see the blood drops appear and run down the character’s face and if you look closer you can also see sweat appear that also moves on the skin surface (slower than the blood). I didn’t see any tears, but I’m guessing that effect may be something that will be tied to an emote you can manually trigger or that will appear via other triggers (ie. pain from wounds and/or damage to your character).

I’m not sure if this bug was just a very prelim test to see if they can incorporate rain VFX and wetness using the Blood, Sweat, and Tears overlay to show rain drops on skin, at which point I would think they would just need to retexture the blood VFX to be the same color as the rain water and have that be a rain specific overlay in addition to blood, sweat, and tears. Very neat to see either way.

Rain produces blood on the skin https://issue-council.robertsspaceindustries.com/projects/STAR-CITIZEN/issues/STARC-169886