Fotos importadas mudando de cor

So, according to info in your second screenshot you images are in the HEIC format. Probably from an iPhone.

Hmm, I was going to comment, but I need to research as my comment may be absolutely wrong. However I will leave the above in place as the inserted screenshot made  to other members may help (at least one key member absolutely hates attachments)absolutely

what is bugging me (for the community is:

• A question is, are HEIC images in phone RAW, or are they Raster.?
• If Raster, does LrC treat them in terms of preview creation just like a JPEG, or is some conversion still occurring as if RAW?

Raw files are always in color, even if you shot with the camera set to B&W. In the Lightroom preferences - presets you can select 'Camera Settings' as default for imported raw files however. In that case Lightroom will read those camera settings and apply them on import, meaning your images should be changed to B&W if your camera was set to B&W.

I cannot view attachments here at the Adobe Forums. Could you please include your screen captures by clicking on the "Insert Photos" icon?

From your description, when you import photos into LrC, the colors originally shown are the JPG preview created by the camera that is embedded in the RAW file. Within seconds, LrC generates its own rendering of the RAW photo, which can be (and usually is) different than what is seen in the JPG preview. So there is nothing wrong with this happening, and in fact, it cannot be turned off.